One effect of global warming is that heat loving wildlife will migrate towards us and ultimately the poles and our temperate wildlife will move ahead of them. It is therefore reasonable to assume that at some point termites and other (sub)tropical species will eventually find their way here. I remember headlines from a good few years ago saying that termites had been found eating a bungalow in Cornwall, so clearly it is possible. Whilst all the resources of the environment agency could eliminate one infestation they won’t manage to prevent mass migration.
So, when considering climate adaptation, who among us is taking future pests into account? Not me, so far.
I was also thinking about my future EWI. Apart from the bottom metre, which I want more damp resistant, I was thinking of wood fibre. These new pests wouldn’t even need to get into my house to start degrading (eating) it.
What are forum members views on this?
I have seen building work undertaken in Zambia and termite deterrence is a major groundworks step between trenching and laying the foundations. Even then, no wooden object, such as door frames, touch the floor. The site I visited had a dormant stage before second fit while waiting for the next tranche of finance. When I inspected it I found termite tunnels up the bathroom walls and into the (timber) loft. That was an expensive oversight. They had got in via the gaps around the waste pipe. Even Zambian family members hadn’t recognised them. It took the mzungu in-law, who had watched too many wildlife documentaries to identify the problem.
I had some experience of subterranean termites (the type you met in Zambia) when I worked in the Caribbean. The termites depend on their connection to their nests in the ground, so even if one finds that they have got up into the building, they can be eliminated simply by destroying their mud-covered tunnels. As you mention, if they can find a discrete route to the base of a door frame, then they can then eat their way up undetected.
Back to Earth have a video chat about pests generally in wood fibre. They don’t mention termites but they do say that, for example, they have never come across an ant infestation. Even assuming that termites find EWI wood fibre digestible, I think that as long as their only route in is via mud-covered tunnels running up the face of your rendered (EPS?) plinth, then you can spot them and deal with them. If your EWI has a rainscreen and cavity rather than direct render, or if the EWI is applied with dot and dab rather than a full bed of mortar, then exclusion could be tricky without application of chemicals.
I hadn’t thought about termites so I’m glad that in my own wood fibre EWI installation, currently in progress, the builder decided to exceed my spec and go for full bed throughout. The plinth is based on Back to Earth’s excellent detail (scroll down for the solid wall version), with the EPS fully bedded and encapsulated and no obvious concealed route for future termites.
There are also drywood termites which nest in the timber and don’t require a ground connection. I did not come across them. They are more picky about the climate, much less widespread and I think they are less voracious.
Thinking about termites more generally: if they did become endemic, then it would be curtains for the suspended timber floor. We’d probably just have to replace them all with solid floors. Termites would also love the standard UK concrete ground floor with an unsealed butt joint at the edge providing easy access to a yummy skirting.
Whole-house retrofit good practice is to seal such edges for airtightness, along with any other penetrations like services entries, which is surely also good defence against termites.
Airtightness products are probably not termite proof. A few bites and they’d get through but being airtight the termites wouldn’t smell that there was food on the other side, so would hopefully leave well alone.
As you say, removing the surface tunnels stops immediate termite activity and that is exactly what I did. The only tool I had to hand was a screwdriver and I used that to scrape off all visible tunnels, which gave a respite period to treat the problem at source.
I’ve just viewed the video and read the plinth installation instructions and as you say, the instructions are excellent.
I just looked up a termite’s digestive system, as one does, and they digest cellulose. The article didn’t mention lignin, so probably “wet processed” wood fibre is ok. I’m not so sure about the try type.