Advice on rebuilding following storms
Brief project / assignment description : Advice on materials to rebuild mud and earth houses which collapsed during 3 day storm of driving rain and high winds. Local architect advises brick, cement and metal but the area is cold in winter and hot in summer. Brick and cement constructions there are poorly built and very cold. Walls of natural material houses were 1m thick. Houses that were cement and brick still suffered extreme damage. Local architect suggesting mixing stone construction ground floors and putting metal rods and cement construction pillars on 2nd floor and filling in between pillars with bricks. Surely using the natural stone with a strong mortar mix to repoint the stonework on ground floors then rebuilding in stone with mortar and to cover walls in a coating to include mud, hay, cement and breathable waterproofing would be preferable with another coat of waterproofing over the whole coating of the houses? This would not be washed out in lashing rain .
Which organisations will use this advice? : Baraka Community Partnerships, Homestays Morocco and other charities we are trying to get involved in the rebuilding.
Full details of technical support request : Architectural advice. Traditional buildings were stone and earth construction stood for over 100 years in most cases. Once in a lifetime storm event destroyed many. Feel villagers are being given poor advice that will be unsustainable, too expensive and impractical for where the villagers are ;1900m above sea level in High Atlas Mountains Morocco.
I think best solution for improving strength of adobe construction is mixing of lime with soil in mud bricks and mud plaster that astonishingly improves strength of soil while the proportion of mixing lime with soil depends upon existing soil properties which can be easily determined through shrink box test .Currently DFID has constructed lime stabilized shelters for flood affected families in Sindh Pakistan, considering various DRR resilient aspects . Technical support is being obtained from Straw built consultancy which has very remarkable experience in proper usage of lime. Please find similar executed shelter design attached for your guidance. Shelter programme DFID.pdf
I'd take the time to check again how different constructions fared in the atrocious weather. As you say, the houses had stood for many years but the weather was freak.
Talk to local people who saw how buildings of interest failed. Did anyone take vdieos with their phones?
High winds and driving rain mean it's really important to have strong and effective load paths and well maintained roofs and wall renderings which, would not be the case as the weather was so unusual.
This problem is not so much about finding what would survive and convincing people to change how they build it's more about convincing people to agree amongst themselves what needs to be done.
From a technology perspective I'd see what survived and talk to different groups: men, women, skilled workers, contractors.
From a changing minds and encouraging people to find what they are willing and able to do I would use the PASSA approach developed by the IFRC.
All the best with this challenge.
You are right that local building techniques and materials should be used if possible, and what you suggest makes sense, if only for making sure people can then maintain their houses afterwards. The resources pointed out by Mary Allen are very good for finding good waterproofing; you can also check out Skat's housing resources, of which many are in French.
My main concerns in your case are:
- Whether you can have suitable roof anchoring / bracing to prevent the roof from flying away during a storm (you can do this with stones, just making sure you are considering it).
- How often such events occur, in order to analyse the cost of rebuilding cheaply and often vs potentially building something more expensive but that will last longer.
- And out of curiosity, why the inhabitants felt the need to consult an architect if they have been using such techniques for a long time - is it because they actually want to upgrade, because such disasters happen too often and they mistrust traditional techniques...?
Could be a difficult one without spending money. Given northern Maroc is an earthquake prone country, buildings, especially 2 stories and more, need to be well designed and built to resist this. So reinforced concrete columns and beams, and possibly further vertical and horizontal reinforcing in the walls. Old style houses with metre thick walls - same as I live in in southern Spain - are quite good for tremors, as they tend to move and then settle again, but in any real quake or heavy rain & wind, if the walls don't have an external waterproof plaster, are vulnerable and prone to collapse.
What are local building codes? Any new-build should conform to these as a minimum.
This thread is public, all members of KnowledgePoint can read this page.