Hi guys, we are currently sale agreed on a property and have just had the survey completed. One of the issues raised is that the house is in an area of high radon. From what I can see online, the test for radon needs to be carried out over three months so it's not really possible to get it done in advance of the purchase. A few people have told me anecdotely that it's quite a big job to retrospectively get barriers in place from the gas, but looking at the EPA website, it seems all that is required is a radon sump which isn't a big expense. Am I right in thinking that all that is required is a radon sump or would more invasive works be required?
What's the ground-floor construction type? Poured concrete or raised wooden floor? Also what age is the house?
They are poured concrete. The original part of the house is about 100 years old, there is a newer extension maybe 30 years old. No evidence of radon barrier
I did this to about 15 different schools about 10-15 years ago. You dig a hole and trench to an outside wall. Then put in a sump and outside pipe and backfill the concrete. The Radon gas gathers in the sump as radon is a heavy gas. You put a little extractor fan on the pipe outside to suck out the radon. It's very similar to the extractor fans you have in toilets. That's all. Very easy. You can put thought into where you'll have the sump and trench. For example if you've a room with a carpet it's very easy to lift up the carpet and dig the hole and trench or do it in an area of laminate timber that's easy to lift and reinstate. Otherwise pick an area where you were intending to replace the floor covering soon. Don't pick an area that you've recently laid a new tiled floor for example. I can't remember the rules exactly but think the sump will cover an area 7.5 meters radius from where you place it. Something like that so keep it central ish in the house or you'll need two.
The way more intrusive way would be to rip up the whole floor everywhere. Dig down and then put in a new radon barrier over the whole house and then backfill the concrete. This is a massive costly amount of work.