Having constructed a demonstration house for the community, we think the timber is being eaten by termites. How can we prevent this happening when families build their own shelters?
This is a question that I've been asked in the field so I wanted to share it with everyone on KnowledgePoint
Thank you for your question. Termite infestation can be as devastating as fire for timber, and a major issue if the timber elements are structural in any way.
First, try to confirm whether the insects are termites. Try Google/Images ‘termite damage’ to find information on a range of different termites and the damage they cause. Generally termites are shaped like large ants, but pale in colour and with longer bodies. They may have wings depending on which type of termite they are. They leave tunnels in timber but these sometimes these will only be seen if you cut through the timber.
Seek specialist advice, especially on whether there are any local laws or customs governing the disposal of infested timber, as it may need to be treated. You may also need to treat the site beneath and around the shelter to prevent the spread of infestation. Find out whether termite infestation is a widespread problem in the area as this will inform your decision whether to pursue timber as a key material in your shelters.
Secondly, decide if you must continue to use timber in your shelters or whether you can consider other materials. Alternative materials must be considered in consultation with the community to ensure any social and maintenance implications are acceptable. The cost of alternatives will also be a strong factor. For structural elements masonry walls, metal columns and beams could be considered, but include your structural engineer in this decision. Metal could also be considered for doors and windows, if available.
If no alternatives are possible, then revisit your design and specification and make sure that the timber elements will be protected from future infestation. General information can be found here:
‘Timber: A guide to the planning, use, procurement and logistics of timber as a construction material in humanitarian relief’ (http://www.humanitariantimber.org/)
Advice on designing to build out termites can be found at D.4 Termites, pests and rot p75. Section B, p19 covers specification, and treating timber can be found at B.6 Treatments p34.
However, local knowledge is a key source of information about timber types that are less susceptible to infestation and treatment methods that will work safely in the local environment.
There are somethings that can be used for termites. No guarentees about the best I have found. 1st. Peppermint essential oil 2nd. Diluter bleach. 3rd. radionics is worth checking. 4th. All timber should be painted with diesle, litterally paint it as if the diesel is paint. It soaks in. Diesel is very good for preventing in the first place. I live in an eco house, we have tried these with various pests like ants and termites with mixed results. The diesel is certainly good as a preventative, also if you put wooden beams in a wall cover the ends with plastic bags ie shopping bags and also paint with diesel, this will preserve the beams. Best of luck. Peter J Hughes. www.abigstrategy.com
If it is feasible to change the method of construction, I would suggest not using timber. The Bubblehome method uses very little timber or it can potentially be timber free and thus avoid termites.
3D printing can also potentially offer another low-cost alternative method. There are 3D printing methods that can use any waste plastic. This would be an excellent recycling/upcycling project and a workshop would need to be established onsite, however I believe it would be financially viable and give the community an ongoing income once the construction is complete.
There are also constructive measures to lower the risk of termites.
Make sure the wood isn't in direct contact with the soil, but rather on some kind of concrete foundation. This also makes it easier to spot the typical tunnels the termites build, and you can train the inhabitants how to spot and destry them (but they most likely know already). See a picture of these tunnels here: http://www.masseyservices.com/wp-cont...
In addition a simple "termite shield" out of GI sheet metal is easy to do and can help a lot (as it makes it very difficult for the termites to build their tunnels). See here: http://buildingadvisor.com/wp-content...
Last but not least, make sure the wood is installed in a way that it can quickly dry, which no deep creases where moisture gets stuck. This is more a general thing to prevent moulding of wood, but it probably also discourages termites.
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