Repairing radon barrier

ennisjim

Hi,

I am at the stage where I need to repair radon barrier prior to laying floor insulation. There are lots of small nicks (<1cm) which I was planning to repair using patches of cutoffs stuck on using a flexible adhesive/sealant (Sikaflex). Nobody advised me to use this approach, just came up with it myself, so if anyone has better ideas I would be interested in hearing them. There is a tape but it comes in big rolls and costs about €40.

However, the repairs which concern me most are the big 'holes' which the electrician has cut out for the central vacuum system, and I expect the plumber will do same for waste pipes. I don't think my patching skills will stretch to deal with these. Can anyone advise on best way to handle these tricky repairs.
Unfortunately I don't think these holes can be avoided. Radon barrier itself is beneath 125mm concrete slab but this rises over first block of inner leaf (block-built with cavity). Waste pipes, etc will most likely be sitting on floor slab which is about 100mm below where radon barrier exits the inner leaf.

De_man

using patches of cutoffs stuck on using a flexible adhesive/sealant (Sikaflex).

Jim imho a waste of time,(i had tried it) each adhesive tub cost me 8.50euro a complete waste of time... it doesn't "stick" to the barrier
and quite easily peels off

There is a tape but it comes in big rolls and costs about €40.

You'll get this double sided tape in either market hardware/shannonside for 20euro... for pipes use the proprietary "top hats" you can get these in 4" or 2" these are then attached/sealed using a clip

However, the repairs which concern me most are the big 'holes' which the electrician has cut out for the central vacuum system, and I expect the plumber will do same for waste pipes.

again "top hats" should do the trick for you it's going to be very difficult to repair properly

ennisjim

Thanks De man for the advice. Much appreciated.

I'll have a look for the 'top hats'. Do you know if they need to fitted as the pipes are installed or can they be put on later ?

Also is there anything you think I should tell my plumber before he starts cutting the holes to ensure that I can use these 'top hats' ? I suppose for example that he needs to cut the hole in a X and leave excess for clips to hold on to ?

muffler

ennisjim wrote:

I'll have a look for the 'top hats'. Do you know if they need to fitted as the pipes are installed or can they be put on later ?

Also is there anything you think I should tell my plumber before he starts cutting the holes to ensure that I can use these 'top hats'

The hats are better going on as soon as possible as I take it you will be proceeding with sub floors etc in the very near future.

Tell your plumber to keep all cuts in the membrane to the bare minimum

ennisjim

Thanks Muffler. Sounds like these hats are meant to be fitted before subfloor.

Unfortunately the subfloor has been in for many months. It is 5" thick with radon barrier beneath it. It rises over the first inner leaf block and is exposed for vertical 4" before going out through inner block leaf. My problem relates to sealing the holes (4", 2") which I expect will be cut in this 4" vertical (and also some holes cut by electrician for central vacuum fittings).
I must get to hardware store and get a look at these top hats but I'm beginning to fell that these will be very hard (if not impossible) to fit in my situation.

Sorry if my explanation of the arrangement of the radon barrier is hard to understand. Must take a picture or two and post them.

ennisjim

The other obvious option is to bring pipes through walls above the radon barrier level, but while this may work for 2" wastes, the 4" wastes would then be visible somewhat above the finished floor level and I'd like to try to avoid that and try to keep all waste pipes hidden below finished floor level.