Hurricane Procedures Manual

Link to sections I, II and III

Section IV. Structural Vulnerability and Loss-Reduction Techniques

INTRODUCTION

The section provides guidelines for vulnerability assessments; acceptable criteria and codes for design of structures; performance specifications for procurement; guidelines for contracting, briefing and monitoring of consultants engaged to undertake vulnerability analyses on existing facilities; procedures for the reduction of vulnerability of existing installations including routine and preventative maintenance and retrofitting. The ultimate goal is to reduce the element of surprise by providing buildings and structures with predictable performance at affordable costs.

The review of damage to most buildings from recent hurricanes in the Caribbean showed that roof failure was the primary cause of problems, leading in some cases to complete collapse of the walls. Some roof structures failed as in a hotel in St. Thomas, but generally, the failures can be attributed to the use of light weight roofing material such as 26 gauge galvanised sheeting or aluminum sheeting. Some roofs remained partially intact but the damage to windows, doors and internal partitions was significant. It is recognised that after hurricane damage has occurred there must be a hasty response to the damage by replacing the damaged facilities as quickly as possible, especially in those cases where the hotel has guests. However, it is disturbing to note that reconstruction of many of the hotels which suffered from the recent hurricanes has been based on the same design concepts and the same materials which led to the failures have been used again.

Providing comfortable and safe leisure facilities as well as reducing insurance premiums should be an important objective of hoteliers throughout the Caribbean. Insurance and reinsurance premiums are becoming more expensive and difficult to obtain for facilities which are unable to prove their structural integrity.

There should be a medium or long term plan for upgrading the structure of all hotels to enable the buildings to resist the known hazards.

HOW HURRICANES AFFECT BUILDING

Hurricanes subject buildings to winds from several different directions, heavy rains, and in some cases storm surge. Buildings must therefore be designed to resist not only high wind speed from all directions, but heavy rain and storm surge.

Wind

Wind damage is caused by wrenching and bending forces imposed by gusting winds and the rapid increase in wind force as wind speed increases. With a doubling in wind speed the wind force on the structure increases four times. Wind striking a building produces pressure which pushes against the building on the windward side, and suction which pulls the building on the leeward side. Failure may occur when the external pressure and suction on the wall combine to push and pull the building off its foundation.

If the building is not securely tied to its foundation, and the walls cannot resist the push/pull forces subjected to them, the structure tends to collapse, starting at the roof, with the building leaning in the direction of the wind.

Hurricane winds can also lift the roofs of buildings. In most cases this uplifting effect is the result of the difference in the speed of the wind over the roof. Lower pressures on the leeward side can cause the entire roof to lift up off the walls.

Rain

Wind entering the structure through broken or open windows and doors can add to this lifting effect.

The torrential rains that result from hurricanes can intensify flood damage to those facilities affected by storm surge, and can also cause flooding in non-coastal areas. The indirect effects include power outages and the saturation of the interior of buildings with salt and water.

Storm Surge

Storm surge can result in great damage to facilities, even if the hurricane is at some distance away from the coast. The force of winds can push waves toward the shore causing significantly higher water levels at the coastline. The resulting flooding can cause considerable damage, even to properties which are in areas where wind damage is negligible, and severe damage to those properties in areas that are directly hit by hurricane force winds.

QUALITY CONTROL IN CONSTRUCTION

General

After a disaster, avoidable structural damage is a major culprit. Such structural damage is mainly due to inadequate control of quality at all stages of the process - design, detailing, construction and maintenance.

Formal quality assurance procedures should be adopted to ensure that buildings are designed and constructed in accordance with the relevant standards and particularly that proper detailing has been done.

The Regulatory Environment

Building Codes

Checking of compliance with required standards is very important. There is no need to wait for setting up an elaborate inspectorate before mandating building codes. The system of check or review consultants (bureaux de contrôle), routinely used in French territories, is also used with variations in Colombia and in Canada (British Columbia). It has been used on several major projects in the Commonwealth Caribbean, principally at the instigation of catastrophe-insurance providers. Other building codes notably the OECS and Turks and Caicos Codes also mandate the use of a special inspector for the review of plans and construction for important buildings. The review consultant should not be otherwise involved with the project and should report to the owner on all critical stages of the project.

Codes and Standards

The Caribbean Uniform Building Code (CUBiC) contains building standards which if properly used will reduce the vulnerability of structures to natural hazards.

The Code contains Sections on:

• Administration of the Code
• Structural Design Requirements
• Occupancy, Fire Safety and Public Health Requirements

The technical standards in the OECS Codes are based on the CUBiC standards, but building regulation in each territory is different. Two OECS countries have approved or passed legislation mandating the use of the Code.

However, it is recommended that the CUBiC standards or other appropriate codes be used by all design professionals in the CHA member countries. The mandatory implementation of a good code with appropriate standards is likely to lead to the reduction in the cost of safe buildings by encouraging more appropriate conceptual designs.

Earthquakes versus Hurricanes

There is a basic difference in the performance expectations of buildings with respect to hurricanes and earthquakes. A building is expected to survive its "design hurricane" with virtually no damage. Even a catastrophic hurricane should only lead to repairable damage. On the other hand, the "design earthquake" is expected to cause (hopefully repairable) damage. A catastrophic earthquake may result in irreparable damage and the building must be demolished. In such an event success is measured by the absence of deaths and serious injuries. The table below compares these issues.

MAIN DIFFERENCES BETWEEN HURRICANES AND EARTHQUAKES

Source: The Arup Journal

CRITERIA FOR NEW CONSTRUCTION

There are a number of areas to which careful consideration should be given during the construction of a new hotel. These include:

• Site and orientation
• Shape of the facility
• Foundations
• Framing and cladding
• Roofs
• Porches
• Shutters

SITE AND ORIENTATION

• Sites should be sheltered and be accessible at all times from centres of population.
• Avoid building on steep slopes where there is little shelter from high winds.
• If steep slopes cannot be avoided, they should be cut in as shown in Figure 1, Appendix II. The task of supporting structures on steep slopes can be difficult and most times expose the underside of the structure, making it easy to topple in high winds.
• When cutting into slopes for construction, pay attention to the cut to ensure that erosion and landslides will not result from the site work.
• The earth should be cut below the ‘slippage’ angle or angle of repose for the soil type under consideration.
• Hill tops should be avoided as they are less protected from high winds.
• Topography should allow for easy access by helicopter.
• Site should not be restricted in order to allow for the temporary extension of facilities.
• Where there is a history of flooding in the region hotel owners should acquaint themselves with the history of the area before deciding to construct; this would help to minimise loss of property and life when flooding occurs.
• Orientation of buildings is not critical as hurricane wind forces can be from any direction and vary continuously.
• Avoid "Pockets" in building plans.

SHAPE OF FACILITIES

• The shape of the facility is an important factor to be considered when thinking of resistance to high winds.
• Avoid ‘T’ or ‘L’ shaped houses as they are vulnerable to high winds because they channel the wind into the junction of the two wings, leading to failure. (Figure 2 in Appendix II) When building rectangular shaped houses, the best length to width ratio is 3:1 or less.
• Roofs should be designed to provide resistance to high winds and should be steep (£ 30 degrees).

FOUNDATIONS

• Foundation weights should be great enough to avoid overturning or ‘uprooting’ of structure.
• Foundations should be reinforced with the use of mild steel bars, and bars should project beyond the foundation by at least 12 to 14 inches to facilitate the securing of the structure to the foundation.
• The footing of the foundation should be specific to hotels.
• If wood posts are used instead of concrete blocks or column foundation, the post should be treated with preservative and then buried in concrete at least 4 to 8 inches into the ground.
• The post should have a minimum dimension of 6 x 6 inches.
• The minimum diameter for round posts should be 8 inches, the hole in which the pole is placed should be larger than the post to accommodate the backfill.
• Foundations of buildings located in flood plains must be designed to withstand dynamic water force and battering action from floating debris, and the effects of erosion due to scouring.

FRAMING

• Cladding material used should provide sufficient strength and adequate bracing to withstand high winds.
• Studs should be located at 2'-0" centres with midway noggins.
• Studs should be doubled around openings (doors, windows) as openings in a wooden structure tend to weaken it.
• Metal straps (T’s and L’s) plus corner braces must be used to secure studs to top and bottom plates and at the corners of the structure.
• The space between the roof and wall should be closed up. Ventilation space should be left in Gable ends.
• Concrete block and clay block infill panels should be reinforced and tied to the main structure to avoid shearing, ‘popping’ or collapse.
• Design of fixings is important as this provides strength and flexibility.
• Joints and junction of panels should be carefully designed against leaking.
• Glass curtain wall systems must be avoided, or protected against flying debris.

ROOFS

• Avoid half porches, as wind trapped underneath an open or half porch will increase high uplift forces on the roof.
• If half porches are to be constructed strengthened ceilings should be provided.
• Roofs of full porches should be separated from the rest of the house so that during hurricane failure of the porch, the main structure will not be damaged.

SHUTTERS AND WINDOWS

Shutters

This is a disappearing feature in an area of the world where it is most needed. Shutters seem to be considered an unattractive feature and is usually overlooked in modern construction. However their construction should not be overlooked as the glass doors and windows offer very little resistance to high winds. Therefore:

• Shutters should be provided for all windows.
• If shutters are removable, they should be able to be installed quickly and easily.
• Construction of shutters also avoid problems created in hanging or locating elements immediately before hurricanes.

Windows

• Areas of glass should be limited and protected.
• Glass should be reinforced or otherwise prevented from shattering.
• Timber or metal louvres have been proven to have the highest resistance from shattering, while glass is prone to shattering from flying debris.
• All windows should be carefully designed, with a properly fixed frame to avoid entire banks of windows being blown in or sucked out.
• Large window areas must be carefully constructed.
• Awning type windows are generally not recommended as those that are available are structurally inferior.

DESIGN AND CONSTRUCTION RECOMMENDATIONS

1. Have all parts of buildings (doors roofs, cladding) designed to withstand high wind pressure including suction.
2. Obtain the necessary Permits for building from the Local Authority.
3. Have detailed drawings and specifications which cover aspects of construction.
4. Ensure that persons involved in construction are sufficiently experienced and qualified in hurricane and flood resistance.
5. Secure all plates to foundations by means of bolts, straps, wood bracing or using special connectors to resist wind or water pressures.
6. Secure all studs to sill plates and top plates with metal connectors or any other straps that may be available.
7. Ensure that metal straps or connectors have been used to make a positive connection from the foundation to the structural members of the roof.
8. Make certain that all materials used and techniques employed provide adequate strength for withstanding potential hazards.

STRUCTURAL VULNERABILITY AUDITS

Structural vulnerability audits should be conducted by a qualified engineer in collaboration with a geotechnical engineer. An important task in this assessment is an inspection survey of all the buildings to be audited.

The three main methods of conducting vulnerability audits are :

• Detailed analytical method
• Approximate analytical method
• Field evaluation method

The Field Evaluation Method uses data obtained from visual inspection and is widely used. It provides an assessment based on past experiences of the buildings with similar geometry, stiffness characteristics, material types, connections and anchorages; it expresses the assessment in general subjective terms such as fair, poor, good, with respect to resistance to extreme winds etc. In the absence of subsoil information, the method also assumes average soil conditions and effects.

This method assigns a rating to the various main characteristics such as symmetry and quantity of resisting elements, anchorage and diaphragm stiffness. The individual ratings are then combined into a composite rating which provides the final assessment.

ROOFS

The failure of the roof exposes the interior of buildings to devastation and often contributes to the weakening and further collapse of the remaining structure.

CHECK FOR THESE STANDARDS!

• Hip or gable shaped roofs with 30 degree slope minimum.
• Over hang of approximately 8" horizontal, unless enclosed.
• Ventilation installed in gable ends facing away from the hurricane winds.
• Rafters attached to wall plate with twisted metal straps.
• rafters located at 2' - 0".
• Every second set of rafters connected by collars or ties beneath the ridge board.
• Cross laths (purlins) located at 1'-0".
• Galvanized sheets of no thinner than 26 gauge should be used. (24 gauge is the recommended thickness).
• Galvanized sheets should overlap to at least one complete corrugation but preferably two complete corrugations.
• Galvanized sheet should overlap at least 10" when they are joined lengthwise.
• Galvanized sheet should be nailed at the top of every corrugation; at eave and ridge Board every second corrugation and lath/purlins.
• Ridge is capped and nailed or washered bolts used for roofing.
• Dome head galvanized nails or washered bolts used for roofing.
• Porch/veranda roof is separate from building roof, and can break away.
• If corrugated metal or light sheet metal is used, CHECK!!
  • the gauge of metal should be regulated; twenty four grams for galvanised steel and twenty grams for aluminum.
  • frequency of spacing and type of fixing should be carefully selected and all nailing should be clinched.
  • waterproof washers should be used to avoid loosening by vibration.
  • fixing of purlin to rafters to be carefully controlled.
  • plates should be tied to ring beams or other structures at regular intervals; and through main walls to foundations at selected points.
  • extended eaves should be avoided.
  • pockets under eaves should be minimised by boarding or sheeting to the underside. Detail at ends of eaves should protect open edges of sheet covering to avoid uplift.
  • fascia boards must be installed.
  • ventilation should be provided to boxed eaves to remove humidity and most importantly to equalise the interior and exterior pressures; they should be placed in overhangs.
  • eaves should be as short as possible; shorter eaves and reduce the upward thrust by the action of hurricane winds.
  • gutters should be securely fixed.
  • sheet and ridge cap should be made to over lap the barge board and be secured with 1" nails.
• Pitch of the roof should be between 30° and 40° with closed gables.
• Timber flat roofs membrane or built-up roofing are not recommended.
• Laths should not be placed flat but on edge and should be not more that 2'-0'’ apart.
• Row of roofing nails at the ridge and eave of the roof should be one nail for each corrugation; for rows in between, there should be one nail every other corrugation.
• Ridge laps should be 6" - 8" to prevent leaks caused by driving rain and capillary action.
• Nail collar ties should be nailed to the side of the rafters, and not the face, so as to avoid the nails pulling out.
• Replace all loose, broken and corroded sheets and tiles.
• Replace rotten purlins and rafters making sure that the drive screws are driven into solid material and cannot be pulled out easily.
• Replace rotten wall plate to be sure it is not rotten- if so, replace it and secure the plate to the wall by bolts.
• Along the eaves and ridge, increase the number of drive screws in the roof sheets by at least 50 percent as the pressures are greatest in these areas.
• Install hurricane clips to connect the studs to the plate and to connect the roof rafters to the studs- this is an important exercise and is not costly.
• Try to install a clip on each rafter and use metal plates made of cut galvanised sheet to connect the members of the roof rafters together, nails holding the timbers together are easily pulled out especially where the timber is not sound, metal or wooden straps are necessary (Figure 4).
• Overhanging eaves should be sealed, this reduces vulnerability. Phase work as ceiling may be expensive.
• If the roof is a gable, you may be able to install louvres in the gables just under the ridge to act as ventilators-this would reduce the pressures lifting the roof off.
• If the verandah roof (or balcony roofs) is not separate from the main roof, you will have to strengthen the roof at the junction of the balcony roof with the main roof, by increasing the hurricane clips on the rafters and by increasing the number of drive screws at the eave of the balcony roof and also at the eave of the main roof.
• The connections of the supports of the balcony roof must also be strengthened. Ensure columns supporting the balcony roof are firmly connected to the ground or floor beam and to the roof plate. Very often the metal connections are rusted. They should be replaced immediately.
• If possible, board in the verandah so as to prevent upward pressures on the roof, the vulnerability of such roofs remains high. It is recommended that the balcony roofs be separated from the main roof.
• Check to see if the equipment mounted on the roof is firmly fixed to the roof underlying structure. If not, arrange to have the mountings installed.

Emphasis should be placed on the following areas:

FOUNDATION

Existing structures which do not meet construction standards for foundations should be improved by the following :

• Building proper pillars and securing the structure to them.
• Strengthening wooden pillars by excavating around the pillars and casting into the ground with concrete 1:2:3 and bracing the pillars to provide lateral support to resist wind action (Figure 3 in Appendix II).

Where there are buildings with reinforced concrete block pillars with no projecting steel bars left to help secure the structure to the foundation, the installation of a metal strap fastened to the pillars which in turn is nailed to the bottom plate can offer some measure resistance.

FRAMING

• installation of additional studding and noggins can be done easily, as well as the installation of T’s and L’s and corner bracing.
• T’s should be used to connect the studs to the bottom and top plates of the skeletal frame of the building.
• L’s should be used to connect the corners of the bottom and top plate.

WINDOWS AND SHUTTERS

• Simple and quick methods of shuttering or shielding should be provided to all windows.
• Traditional or metal roller shutters are alternatives.
• Ensure operators on all louvre windows are working.
• Replace all broken glass in window.

LANDS AND GROUNDS

• Establish a programme for periodic inspection and pruning of trees in built-up areas.
• Inspect terraced areas and slopes periodically, and maintain to avoid erosion
• Inspect ground surface ingredients and drainage systems periodically and keep free of dirt and debris.
• Institute a programme of planting special trees and shrubs on steep slopes to combat land slippage.

FOUNDATIONS

• Solid cement/concrete pillars firmly embedded 18 inches in ground with 1/2" rebar extending 12 inches above foundation.
• Wooden pillars (6" x 6" minimum or 8" diameter) treated lumber, sunk more than 4 feet into the ground.

WALLS

• Wall plate/sill attached to cement foundation/pillars by bolted rebar.
• Wall plate/sill attached to wooden pillars by straps and nails.
• Floor joists toe-nailed to wall plate.
• Wall uprights (studs) fixed to sill and top wall plate with hurricane straps.
• Wall uprights (studs) located at 1' - 0" centres.
• Double studs around doors and windows and cross braces at corners.

WINDOWS/DOORS

• Shutters made and attached for rapid closing or shutters pre-made and stored to be nailed in place before storm strikes.
• Staff trained to keep all entrances closed throughout storm period and/or open Entrance on opposite sides of buildings to allow air pressure to neutralize.

DOORS AND WINDOWS

• Examine doors and windows, they must close tightly.
• Ensure that operators on louvre windows are all working.
• Replace all broken glass in windows.
• Check hurricane shutters (if any) to see that they work.
• If the building has large glass sliding doors or glass windows without hurricane shutters, there would need to be sheets of plywood on hand for protecting the glass when a hurricane warning is announced. Permanent hurricane shutters built of timber would be useful; or aluminum hoods which close to become a hurricane shutter can be bought and installed permanently.
• Alternatively, the hotel owner may wish to protect the glass (and the contents of the hotel) by installing polyvinyl butryal laminated glass - this is a preferred option if the cost can be absorbed.

EXTERNAL AREAS

• • Flooding often follows a hurricane - check to see high water mark in previous heavy rain storms and ensure that drains are cleared to carry the rain water away from the building and that no storm water can get into the building.
  • You should try to dig trenches around the building so as to lead water away from the building especially if the floor is below flood level.

MAINTENANCE AS A MITIGATION TOOL

The hotel building must be in a reasonable condition if it is to withstand the forces of the hurricane. Deferred maintenance is counter-productive as the cost of major renovation becomes inevitable. This is much greater than the annual amounts needed for adequate maintenance of the buildings and plant.

Hotel owners should make every effort to bring the condition of the buildings and plant to the standard where a normal maintenance system can cope with the maintenance requirements.

Maintenance plans must be included in disaster mitigation plans. A well-operated system of maintenance for buildings and equipment is also a very effective disaster mitigation measure in terms of cost and facility usage. It ensures the most economic way to keep the building and equipment in the best of form for normal use, given the original design and materials.

If a good system for maintenance is not properly organised, funded, staffed and carried out, then all other disaster mitigation methods could prove insufficient. Experience indicates that roofs, walls, and equipment in general are more vulnerable to failure if normally operated at near breakdown or at any level of technical deficiency. The principal activities to be undertaken for maintaining hurricane resistance (in particular) of the hotel include careful inspection.

Inspect:

• foundations and repair as necessary.
• roofs including claddings and repair as necessary.
• for sign of structural failures and repair immediately.
• electrical installations periodically for sign of wear and loose connections which could lead to malfunctioning and correct immediately.
• external drains and manholes and keep free.
• for termite treatment infestation.
• all building fixtures and fittings ; repair and replace as necessary.
• rainwater disposal systems, and maintain to ensure that water flows freely and discharges away from foundations.
• ground water gradients and maintain to ensure run off away from the building.
• ground surface gradients and drainage systems and keep free of dirt and debris.
• piling on wharfs, piers and jetties (timber, steel and concrete) and repair and replace as necessary.
• decks and repair all faults.
• sea walls for signs of structural failure and undermining, and repair as necessary.
• gabions and groynes for signs of instability and correct any defects.

Semi-Annual Reviews

Semi-Annual reviews are performed to the ensure the following:

• check for implementation of the initial vulnerability audit.
• identify overlooked items.
• benefit from new knowledge.
• identify deterioration.
• review maintenance procedures.

These reviews serve to ensure that an adequate maintenance programme is in place. This in turn ensures a good relationship with the insurance industry and will enable the facility to benefit from more favourable catastrophe-insurance premiums.

Proper maintenance should ensure that the facility can:

• function at its designed level at all times
• function for the normal life span of the building and of the plant
• resist the effects of extreme natural events such as hurricanes, floods, and earthquakes without damage to its occupants and with minimal repair or rehabilitation necessary after the passing of the event

All maintenance activities should be systematised and the "anticipate-and- prevent approach" adopted rather than the "react-and-cure approach". Repair is often considered to be the main purpose of the maintenance system, rather than the prevention of the need for repair. The scheduled oiling of door hinges and window operators or the painting of exterior wooden members is necessary to prevent failure of the equipment or rotting of the wooden members.

A comprehensive maintenance system should be instituted by hotel managers, and should comprise:

• organisational structure with clearly defined duties and responsibilities
• an operation maintenance manual and procedures reference for the buildings and equipment
• a management information system to produce reports on budget, stocks, inventories of equipment (numbers and condition), staffing requirements (especially for maintenance operations), etc.
• a preventative maintenance plan for equipment including stand-by equipment and water storage tank
• a building maintenance plan - including roofs, walls, electricity, water lines.
• a continuous maintenance training plan for selected maintenance personnel.

Planning of Maintenance Activities

Maintenance planning activities are normally carried out and should include the development of a detailed annual maintenance budget. The maintenance staff must therefore be trained to examine all parts of the buildings and plant in their care and to record deficiencies. Such lists must be prepared on an annual basis, but this does not preclude the immediate attention to problems which are endemic in many hotels.

Proposed Maintenance Organisation & Staffing

Reporting of work done is also an essential part of the maintenance system. A simple reporting form is included in this report but the hotel manager may wish to devise his own form which may be more responsive to the problems in the hotel. However, the simpler the form the better will be the chances of having the form properly filled out and submitted monthly.

• Hotel assistant manager is responsible to the owner for the efficient operation of the hotel (including the general staff matters, buildings, equipment and grounds) and for the expenditures authorized in the annual estimates.
• Hotel manager delegates to the maintenance superintendent the responsibility for the maintenance of all buildings and plant and for providing advice to the hotel manager on capital requirements and on the condition of the buildings and plant.
• Technical staff (as required) report to the hotel manager (or maintenance superintendent) including: carpenters, plumbers, electricians, painters
• Gardener and cleaning staff report to the hotel’s assistant manager.
• Major repair or renovation projects must be specifically authorized by hotel manager and hotel assistant manager depending on the budget requirements, but normal maintenance and minor repair can be carried out by in-house staff without specific authorization.

Checklists and Frequencies for Maintenance Operations

Three tables are presented covering:

• Table 1.0 - The building interior
• Table 2.0 - The building exterior
• Table 3.0 - The compound

The following abbreviations are used in the tables:

Notes: For frequency the maximum period is given. For operator the person named is the one responsible for seeing that the operation is carried out.

Table 6.1 Building Interior

Annual Budget for Maintenance

Hurricane mitigation and planning should be routinely included in budget preparation and planning, as it makes financial sense to build appropriate maintenance, repair and replacement costs into annual budgets.

The maintenance budget should be of the order of 4% of the current value of the facility per annum and should address :-

• Metal and wood works.
• Equipment which are occasionally used (stand-by equipment) to be regularly tested by its periodic use.
• Repairs leading to moderate improvements.
• Replacements leading to significant improvements (repair versus replacement is an economic issue which should be addressed at this point).
• Regular staff training in the use and operation of equipment.

Maintenance Budget

It is normal for the annual maintenance budget of a hotel with heavy usage to reach 4% of the contemporary capital cost of the building and equipment, assuming that the facilities are in good condition to start with. For hotels, it is estimated that the replacement cost is about US$150,000 per guest room. This figure includes the cost of common and administrative areas but does not include the cost of emergency electricity equipment, water storage or normal furniture and equipment (ff&e).

The maintenance allocation should therefore be no less than US$6,000 per guest room per year plus an allocation of about 8% of ff&e for maintenance of those facilities.

For smaller hotels of less than fifty rooms this allocation of US$ 6,000 per room may be smaller than needed, as the cost of infrastructure maintenance would be proportionately higher than that of a larger hotel.

Proposed Maintenance System

This involves careful review of available data such as drawings, an inspection of the building without invasive testing and a non-mathematical review of existing information on the design and construction of the facility. The consultant engaged to carry out this assessment must be:

• knowledgeable about the effect of hazards on buildings
• be an experienced structural engineer with specific experience in the design of buildings to resist extreme natural events

The hotel owner should determine the level of risk he/she can accept when discussing building or retrofitting plans with the consultant.

Risk Analyses

Risk is a measure of damage and is a function of the hazard (e.g. hurricane) and the vulnerability of the subject. Risk may be measured in money terms, in percentage-loss terms, in terms of deaths or injured and using many other criteria. The criterion chosen depends on the aim of the analysis. Insurance companies would want to determine the financial loss whereas a public heath agency may be more interested in the numbers of injured and fatalities. The hotel owner may be interested in the cost of the repair and renovation, and on the number of days of lost revenue that will ensue if the hurricane damages the property.

Risk analyses (before the event) assist decision makers in planning rationally for future hazardous events. The hotel owner should determine the level of risk he/she can accept when discussing building or retrofitting plans with the consultant.

Analytical Evaluation

Buildings deemed not wholesome subject to qualitative assessment would require analytical evaluation. Such an evaluation is time-consuming and expensive. It would be best if it were carried out when funds are available to implement a retrofitting program.

RETROFITTING

Retrofitting for hurricane resistance can be relatively easy and inexpensive especially if the building is adequately maintained. The determination of a retrofitting program follows the qualitative and analytical evaluations referred to above. Roofs are usually prime targets for retrofitting. Light-weight corrugated roof sheeting is particularly vulnerable because of inadequate fastening systems. Better fasteners are now available, such as the Australian cyclone washer and the French-Caribbean fastening systems for trapezoidal-profile sheeting. Overhanging eaves experience very high uplift loads from the wind. These should be reduced.

Hotel owners may wish to have the conventional glazing in large windows and doors replaced with polyvinyl butryal (PVB) laminated glass, which comes in different thicknesses and with different numbers of laminates to suit different conditions. The building owner may also install shutters that have an everyday function of shading as well as protection of windows in times of storms.

Costs

The costs of retrofitting depend on the conditions of the subject properties. However, work is now being done on the retrofitting of various facilities and some estimates of costs are available.

An unpublished study now underway on buildings and other infrastructure projects in Jamaica, St. Lucia and St. Thomas showed that for the buildings an additional cost of less than 2 percent of the original construction cost would have prevented the damage by the hurricane, and for the infrastructure projects which suffered much worse than the buildings from the hurricanes, an added expenditure of about 11 percent would have prevented disaster.

Other studies have shown that amounts of from 1 percent to 2.2 percent of increased construction costs were needed for strengthening electricity buildings in Barbados and a hospital in Dominica.

Hotel owners/managers should inform their decisions by these findings.

ROLE OF HOTEL OWNER

Hotel staff should provide support for a comprehensive approach to hazard mitigation. The following are guidelines defining the role of the hotel and its staff in planning to mitigate the impacts to hurricanes, and in so doing, maintain the structural integrity of the buildings throughout the facility. Accountability of staff/consultant is necessary for ensuring the soundness of the plant.

The hotel manager has a significant role to play in the construction and maintenance of the hotel. In the first place the hotel owner must:

• Ensure that facilities are designed, built and maintained to function during and immediately after hurricanes, earthquakes, torrential rains and other natural hazards.
• Understand the implications of failure of the building under the hurricane forces.
• Undertake surveys of the vulnerability of the facilities and pursue mitigation actions. Where indicated, it is recommended that the owner engage a review consultant to assist in this task also to carry out twice yearly reviews to:
  • check implementation of retrofitting recommendations
  • identify overlooked items
  • identify deterioration of any part of the system
  • review maintenance procedures and study carefully reports from chief engineer and assistant manager
  • update maintenance procedures and systems where necessary
• Check designs and proposals submitted by the consultants to ensure that the mitigation strategies proposed are satisfactory.
• Appoint a review consultant with thorough knowledge of hotel operations to assist in the review of the plans.

Construction Records and Plans

All too often the owner cannot find the plans of the hotel. These plans are needed for analysing the structure of he hotel for finding where the buried cables are. The owner must therefore:

• Ensure that as-built drawings are produced for all new construction. (As-built drawings are useful for vulnerability assessments, repairs, additions, alterations and post-damage assessments).
• Document all repairs and replacements.
• Duplicate as-built drawings for "working drawing" sets so that a "mint" as-built set is in the archives at all times.

GUIDELINES FOR CHOICE OF CONSULTANTS

The procedures for the procurement of consultants are very often set by the agency financing the project. The procurement procedures will in most cases require that consultants:

• be experienced in the work to be done
• have a track record of successful completion of similar projects
• have the requisite staff - numbers and qualifications - for the project to be worked on
• be informed about the natural hazards that might affect the project and be informed about the techniques for designing for natural hazards resistance
• have the financial ability to carry out the work required, hire and pay staff and pay the necessary expenses before reimbursement by the owner
• negotiate fees and expenses generally on the remuneration schedules of the appropriate professional organisation

Selection Criteria

The selection will also be based on whether the consultant has:

• specific experience in retrofitting
• local knowledge and presence -retrofitting of a building to improve resistance to hurricanes is not a project that can be completed properly and fully without time being spent on the site examining the details of construction and determining the critical components to be strengthened
• professional independence and integrity are important attributes which cannot be overlooked

The consultant must also understand, and be able to interpret the terms of reference in a manner which will provide the owner with the result desired.The terms of reference should be clear and concise and the owner's or manager's desired result explained to the consultant.

Selection Procedures

A short list of not more than four consulting firms is required for the selection of a consultant . The short list should be based on knowledge of the consultants who express an interest in the project and who has the ability to carry out the work. The short listed consultants will be required to submit proposals containing:

• past experience of projects of a similar nature
• details of organisation, project control and financial control
• size and responsibilities of staff
• type of organisation and managerial method proposed for the execution of the work
• quality assurance procedures
• knowledge of local conditions and local resources
• technical approach to the project
• availability of resources
• approach and commitment to technology transfer

The owner should assess proposals, negotiate with the selected firm and conclude an agreement. As an alternative to the competitive method outlined the owner may chose to select a consultant based on first-hand knowledge and past relationships. This is often the safest approach.

Briefing of Consultants

The briefing of consultants is an important task which is very often overlooked. The owner must discuss with the consultant specific issues such as:

• the level of risk that the owner is willing to take
• the expected performance of each section of the hotel when impacted by hurricane winds
• the increases in costs attendant upon higher levels of performance
• the schedule for the consultants work
• responsibilities of each key member of the design team to ensure that there are no gaps in the process
• arrangements for the design of non-structural parts such as windows, doors, and balcony railings
• arrangements for receipt of reports on the consultants progress
• arrangements for remuneration of the consultants fees and expenses
• information to be supplied by the consultant on the problems to be solved by the owner and on the time schedule for their solution
• arrangements and procedures for selecting building contractors
• level of inspection of the construction to be supplied by the consultant and attendant cost.

SUMMARY PREVENTION TIPS

The following steps should be taken by the management team to ensure that the hotel can respond to the hurricane hazard without major damage:

• annual inspections of the buildings and plant in March/April
• inspections of the windows, doors, roofs and drainage ditches must be done in April and repairs effected before the hurricane season
• budget estimates for effective maintenance must be based on detailed examination of the buildings and plant supplemented by reports from the users of the buildings and plant i.e. assistant managers and other staff
• chief engineer and the assistant manager must make monthly reports to the hotel assistant manager detailing work carried out, costs, staff available and the problems to be dealt with during the current financial year and those requiring further examination and/or funding
• hotel manager and owner must engage a consultant to carry out vulnerability assessment of the hotel as soon as possible. This activity is one of urgency as it is the forerunner to proper planning of retrofitting and renovation work which may be needed to prevent the loss of the hotel by a major hurricane
• It is expected that major renovation work which may be necessary will be contracted out and not carried out by the regular maintenance staff.

Link to sections V, VI, VII and appendices