This Toolkit was developed by CDMP to assist with the setting up and monitoring of Safe Building Practice Initiatives attached to Home Improvement Loan Programmes in Credit Unions, to assist such institutions in the production of Disaster Resistant Housing.
Overall description of the programme and goals
How to use the Toolkit
Step 1. Design a Programme
Step 2 Training for staff
Step 3 Monitoring and Supervision
I. Training outline for staff
II. Technical handout for staff
IV. Proposed minimum standard for adoption by the Credit Union
V. Brochure to hand out (not available in online version of this document)
VI. Q's & A's for members to ask of builders
VII. Evaluation forms
VIII. Sources of information
This toolkit is produced as a result of a pilot programme, where, working with two Jamaican Credit Unions, the Caribbean Disaster Mitigation Project introduced safe building practice into the Home Improvement Loans programme that already existed for Credit Union members. During that pilot, lessons were learned and some of the content of this toolkit reflects ideas and ways of working that came out of the pilot. The pilot Programme was carried out by Stephen Hodges, consultant to CDMP.
The goal of the programme is to introduce disaster mitigation and safe building information into the credit union lending process so that the buildings created, refurbished or renovated will survive hazards. The hazards that affect Jamaica are primarily flooding, hurricanes and earthquakes, and the material developed reflects these.
The contents are to enable anyone organizing a disaster mitigation project in a credit union to:
To do this you will need someone with some technical competence to organize the programme and to carry out the supervision of the details used in the houses that the funds help construct.
One of the key issues and lessons of the pilot programme related to the voluntary nature of what was attempted. Credit staff, not being technical, did not feel able to insist on the borrowers putting in safety measures, as they were voluntary, and therefore optional. They suggested that the credit union adopt a set of technical "Minimum. Standards", the use of which would be a condition for the loan. This would make their task easier, as they could insist on the standards, and in addition there would have to be someone technical to inspect the buildings so that the loan could be disbursed.
Choose whether or not your programme will be voluntary or will have mandatory standards, and if it does, review and submit the Minimum Standards to the board of the Credit Union for adoption.
Much of a programme of this nature is raising awareness and commitment to producing safer housing. The credit staff must come "on board" and communicate a concern, as well as the technical issues and brochure to the borrower, that they construct a safe house. If the technical standards are mandatory, they need to explain what is required, and send the minimum standards with the borrower for the attention of the designer or builder.
Keeping records of information given, numbers of buildings affected and, if the standards are made mandatory, sending supervisory personnel to visit and report on the conformity to the standards set are activities that need organizing. One person should be made responsible for the record keeping, and periodically, preparing a report on how the programme is functioning. Remember, good records will allow the Credit Union to assess after a hurricane or other event how effective the programme has been in safeguarding the property of the members.
The Appendices include information that will assist to carry out these activities:
Is the site you have in a flood prone area? If you don't know, ask someone who has lived in the area for a long time. You may have to find some higher ground, or build a plinth or mound of rolled marl to raise the building out of danger. For existing houses, it may be possible to construct walls to keep out the water.
|Extra high winds
If your site is on top of a hill, or you have a clear view of the sea from which hurricane winds may come, the wind will not be slowed down by the buildings and trees as is normal. You will need to be extra careful about overhangs, porches, and all the connections that hold together the parts of your house.
|Big trees too close
Do you have trees that, if a hurricane blows them down, they could fall on the house? Either trim off the top or, if necessary, cut it down. Cutting the top off a tree makes it much stronger, as the trunk has less foliage to be pushed against by the wind.
If the ground that your foundations are dug in is poorly compacted fill, near a steep slope, or held back by a retaining wall, the soil may subside or move away, taking away support from the house. You must have strong foundations and press on the soil as little as possible. A steel "cage" should be used in the foundation. Use wider than normal foundations to spread the load on the ground.
Treat the ground that you dig the foundations in with an insecticide that will control termites. They travel through the ground to reach the building, with part of the nest underground. Watch out for trails going up the walls and treat any damage by cutting out the damaged wood, spraying with insecticide, and replacing with pressure treated lumber.
Strong earth movements during earthquakes can crack your house. Soil settlement, tree roots and clay soils will cause movement that can result in cracks. To resist the cracking, always have steel in the foundations, and where the soil is soft, or a mix of soft and hard, or in clay, a steel "cage", with bars at the top and bottom will keep the foundation from breaking.
|A Reinforced House Frame
Make sure that each panel of blockwork and openings such as verandahs are surrounded by reinforced concrete. Stiffeners in the walls, reinforced foundations and belt beams connect together the walls of the house and prevent cracks from opening up the panels. The ban must overlap at the comers at least 18 ins. (450 mm) to prevent them from separating.
|Wallplate holding down the Roof
In a hurricane the roof can lift up off the walls. Do not feel that bent reinforcing bar can hold down the roof to the walls. In a hurricane, the wind shakes and pulls on the roof. This will straighten out the steel and you will lose your roof. Use bolts set into the belt beam to hold down the wallplate, as these will not let go under stress, at a spacing of 3 to 4 ft. (900 - 1200 mm).
|A roof strapped together
To hold down the rafters to the walls when a hurricane is trying to lift them off the roof, you need Hurricane straps (twisted straps), which nail into the side of the rafter and into the side of the wallplate to hold them together. Fit one strap per rafter all round the walls.
To lessen the force of the wind under the overhang of the roof, keep the overhangs small less that 18 inches (430 mm). This is particularly important where the roof overhangs the gable, as it is not pointing down and is higher off the ground, where the wind is stronger.
|A Protected Main House
Carports and external verandahs and porches suffer both suction from wind above and pressure from below. They are much more likely to blow away than the rest of ft house. It is wise to separate the roofs of these structures from the main house, to protect it from damage should they fail.
|Build everything well
Laths have to be nailed to rafters, and the zinc is nailed to them. To hold the zinc down during a hurricane, there need to be many fixings, preferably two nails where the lath cross the rafter. The laths should be spaced at 2ft 6 inches or closer to share the holding down of the zinc above. It is recommended that 1 x 4 inch laths are used (not 1 x 3), so that the two nails can be used.
|Nail zinc well
Fix zinc down with nails or drivescrews, using one every other corrugation along the edge of the roof, and one every three in the centre of the roof. Where the edge of the zinc overhangs at a gable end, fix it at every corrugation, as the zinc will try to roll up starting from the edge.
|Use good sheeting
If the sheeting is too thin, it will tear off the nails or screws holding it down. Use 26 Camp zinc sheeting (as specified as the minimum in the Building Code), not the thinner 29 or 30 gauges. When using aluminum, which is softer than steel, use 22 gauge. If you have to usee sheeting, use nails at closer spacing to provide more fixing down.
[ ] Is the site prone to flooding?
[ ] Is the site exposed to high winds?
[ ] Are there big trees close to the building?
[ ] Is the ground made of fill, or near a slope or retaining wall?
[ ] Have the foundations been treated for termites?
[ ] Will the foundations have steel in them?
[ ] Will there be stiffeners and all blockwork framed by reinforced concrete?
[ ] Will there be bolts to hold down the wallplate?
[ ] Will there be hurricane straps to hold down the rafters?
[ ] Will the overhangs be less than 18 inches (450 mm)?
[ ] Will carports and external porches be separated from the main structure?
[ ] Will laths be spaced at 2 ft 6 inch (750 mm) or less?
[ ] Will zinc be fixed with drivescrews or with zinc nails every other corrugation, at the edge?
[ ] Will the thickness of the zinc be 26 gauge?
The following are standards designed to ensure housing that is able to resist hazards such as hurricanes and flooding. They do not remove obligations to construct using conditions of the national building code, but are in addition to the requirements under the code. Generally, code provisitions will ensure resistance to earthquakes, providing that they are followed and that standards for concrete quality and reinforcement bar overlaps are met.
The brochure is not included in the online version of this report.
|1. Is the building in a flood-prone area, and if so is it elevated sufficiently above potential flooding?||Yes||No|
|2. Are there big trees close to the building that could do damage in an earthquake or hurricane?||Yes||No|
|3. Is the building on fill, or near a slope or retaining wall?||Yes||No|
|1. Are carports, patios and verandahs separated structurally from other buildings?||Yes||No|
|2. Are overhangs less than 18" (450mm) at eaves and gables?||Yes||No|
|1. Is the minimum depth of foundations 18" (450mm) in good ground or dug to below level of fill?||Yes||No|
|2. Have the foundation trenches been treated for termites?||Yes||No|
|3. Do the foundations have longitudinal steel in them and, if in poor ground, have top and bottom steel with stirrups?||Yes||No|
|1. Are walls built with||Yes||No|
|1. Are the bolts to hold down the wallplate set into the belt beam (and not bent reinforcing bar)?||Yes||No|
|2. Are there hurricane straps to hold down each rafter to the wallplate?||Yes||No|
|3. Are laths spaced at 2ft 6in (750mm) or less?||Yes||No|
|4. Is zinc fixed with drivescrews or with zinc nails every other corrugation at the edge and at every corrugation over the gable end?||Yes||No|
|5. Is the zinc used at least 26 gauge thickness?||Yes||No|
This form is particularly for Programmes where there is an adopted technical standard and, therefore, some form of technical inspection. Where there is no inspection requirement, it is more difficult to keep records of what has been done with the safe building information alone.
Period covered: ________________
|1. Number of clients to whom information has been distributed:|
|2. Number of buildings using loan programme presently:|
|3. Number of houses with completed construction, inspected and full loan disbursed during period:|
|4. Cumulative total of houses strenghtened to date:|
|5. Number of features from information taken into account and supervised:|
|6. Any additional features that should be included in the technical standards:|
|7. Any requirements that are causing difficult for builders to comply with:|
|8. Total number of builders used to date:|
Additional sources of information on Disaster Mitigation, Hazards, Safe Building Practices and Training of builders:
The Office of Disaster Preparedness and Emergency Management
12 Camp Road
Tel: 876 928 5111-4 | Fax: 876 928 5503
Construction Resources and Development Centre (CRDC)
11 Lady Musgrave Ave
Tel: 876 978 4061 | Fax: 876 978 4062
Caribbean Disaster Mitigation Project
Organization of American States/Unit of Sustainable Development and Environment
1889 F Street NW
Washington DC 20006
Tel: 202 458 3006 | Fax 202 458 3560
|CDMP home page: http://www.oas.org/en/cdmp/||Project Contacts||
Page Last Updated: 20 April 2001