Re: Re: Radon Barrier & Insulation
Not quite what I meant about the Insulation Bren 88, of course the insulation has to comply with the regs and should be of the best standard you can get. However, with the floor construction, its not, as you say, just the same as new build, beacause the radon barrier is not fully exposed because the existing walls are in place. My point is that you can’t fully seal it at the existing external wall of the house because you simply won’t have enough radon barrier exposed at the top of the plinth, given that the minimum required lap is normally 150mm on these membranes. How often have you seen even a fraction of that exposed at an external wall. The radon barrier is only effective where it is sealed in a membrane to membrane situation so where you seal it against masonry or plasterwork the radon can still get through, and this is where the benefit of the barrier is lost. If not, in a new build situation why not just stop the radon barrier at the internal leaf of blockwork in a cavity wall rather than bringing it out the to the external wall ? The arrangement you’re talking about is fine where you have either an existing door opening at the external wall, or are forming an opening and can easily access the radon barrier in the existing house, but either side of this you don’t have access to the radon barrier at all.