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Damp proof membrane issues - under floor heating

Postby bob 321 » Mon Jan 02, 2012 10:31 pm


I want to retro fit a wet piped under floor heating system to my existing house.
The house floor is concrete, no idea how deep or what type of construction YET.
The house was built in the UK 1986 and some plans I have (not 100% the house was built precisely to the plans) call for "tiles on screed on 100 concrete on visqueen 1200 on DPM on hardcore bunded with sand". It looks pretty unlikely there will be any insulation.
The ceiling height is 2.3m and while it would be far easier to put 50mm of insulation, pipes and another 50mm of screed I don’t want to lose 100mm of ceiling height, change the doors and stairs. I’m getting to the conclusion I will need to dig up the floor, but need help answering the following :

The floor has a DPM under it which can be seen in places at the inside edges of the exterior walls.
If I excavate each room leaving the area under the interior walls I will probably dig through the DPM. So if I end up with several rooms where the DPM has been dug through, even if I put a new DPM under each area the edges will be coming up at the internal walls.
What would be the consequences of this ? Any other way to do it ?

I plan to drill a few test holes to determine depth and construction materials. Any thoughts on sealing it up if I go through the DPM ?


bob 321
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Simply Build It

Postby welsh brickie » Tue Jan 03, 2012 8:05 am

if you go through the dpm tape any holes with duct tape.
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