taping insuation

cwboy

Quick question

Just about to lay foor insulation.
Do i need to tape it and if so what kind of tape do i use?

going with 100mm xtratherm

thanks

Martron

Nope. if this is on a concrete floor the membrane below it needs taping if there is a joint. so if you have a radon dpm you will need a radon tape..... etc etc

cwboy

ok so radon barrier down and taped then lay insulation then pour concrete.

thanks

Martron

well does not need to be a radon barrier. but you will need a membrane of some sort.

sydthebeat

Martron wrote: »

well does not need to be a radon barrier. but you will need a membrane of some sort.

to be on the safe side, lay a radon membrane...

then insulate..

then lay a 1200 gauge polythene...

then pour concrete.

This second membrane is known as a slipping sheet, but is most useful as a separating layer between the insulation and concrete, as it has been shown that the concrete reacts quite vigurously with the foil on the insulation.....

Martron

what exactly happens? never heard of slipping sheet? is this a new thing?

i have also seeen the memebrane being laid then 100mm of compacted sharp sand. then insulation ....

if you are not in a radon area it would not be necessary . unless the price difference is not too much. also defeats the purpose of having radon membrane then not sealing the joints. so if you going with radon membrane either try and avoid joint but if you have joints ensure that you seal them properly.

would radon sump be cheap than radon membrane?

RKQ

Radon is everywhere but can reach dangerous levels in certain areas. Check the radon map.
All radon joints should be overlapped and taped. A radon sump is highly recommended, cost €30, or you could use 4 bricks and a paving slab.

A damp proof membrane should be overlapped to prevent damp penetration. (A radon barrier is also a d.p.m)

I don't see any reason to tape foil sheets but you could use foil / duck or aluminium tape. Sand blinding would need to be 100% flat - very difficult to achieve!
Slipping sheet of cheap plastic might be a worthwhile measure.

Vertical insulation around the perimeter of the floor is extremely important. More benefical than taping sheets.

LoopyBum

No slipping sheet needed as they're using 100mm Xtratherm, it's not foil backed.

Well the stuff I got wasn't!



Everyone is in a radon area, it's just a matter of how lethal it is in your spot! A radon sump is a lot less hassle than the radon barrier/sheeting and unless radon is bursting up through the ground in your face, the sump is sufficient... by today's standards.. which I've no doubt will change over time... :rolleyes:

cwboy

the xtratherm i got was foil backed. does the slipping sheet need to be taped together much like the radon barrier or will just laying it flat do?

topcatcbr

LoopyBum wrote: »

No slipping sheet needed as they're using 100mm Xtratherm, it's not foil backed.

Well the stuff I got wasn't!



Everyone is in a radon area, it's just a matter of how lethal it is in your spot! A radon sump is a lot less hassle than the radon barrier/sheeting and unless radon is bursting up through the ground in your face, the sump is sufficient... by today's standards.. which I've no doubt will change over time... :rolleyes:

A radon sump is not suffecient on its own. It requires the barrier to be layed also.

LoopyBum

topcatcbr wrote: »

A radon sump is not suffecient on its own. It requires the barrier to be layed also.

Well then I've been screwed!? I don't recall there being any radon sheets, just ordinary builders black plastic ... It didn't say anything on the roll about radon...? Or would it?

sydthebeat

http://www.boards.ie/vbulletin/showthread.php?t=2055085824&highlight=radon



There was a big debate on this issue in the above thread, one which im sure wont start again..

basically loopy, you havent been screwed.....
a radon sump is compulsory whereas a radon barrier isnt. It would be considered by most here to be best practise that a radon membrane is laid, but a 1200 gauge polythene is sufficient in some cases.

This is taken from the RPII site itself....

Since July 1998, every new house is required to incorporate some degree of radon preventive measures at the time of construction in accordance with the revised Building Regulations. The degree of protection required is dependent upon whether or not the site is located within a High Radon Area.

For all parts of the country, the Building Regulations require that new buildings include a potential means of reducing radon levels, should high levels be found in the completed building. In the case of dwellings of normal construction, this is most commonly achieved by means of a radon sump, as described in the Department of the Environment's publication "Radon in Buildings". The Institute recommends that, once occupied, all new buildings should be tested for radon. If the radon level is found to be above the Reference Level then the radon sump, or other means of reducing the radon levels, should be activated.


In High Radon Areas, the Building Regulations require that, in addition to providing a potential means of reducing radon levels, measures should be taken to protect the building from radon in the ground. For a dwelling of normal construction, this means that a fully sealed low-permeability membrane should be provided in addition to a radon sump.

Villain

Ok god not that debate again I got a infraction for the last debate because a mod wouldn't accept that there is area's of low radon.

Basically a Radon barrier should be installed in every new house, its a great for a dpc even if the site is in a low radon area.

LoopyBum

Thanks Syd ...