Insulation under screed and leak!

P

paraicc

Guest
Hello all,

I'm currently building and am waiting to put floor screed in on the bottom floor. I have aproblem in that the front door is currently only 4.5 inches off the finished raft floor. The installers are able to left the door anothe half inch which will give me 5 inches in total. I have been led to believe that ideally I should have 2 inch insulation and 3 inch screed. I can't have that as I would have no space left for my finished floor. I am thinking about going with 30mm or 35mm kingspan with a 3 inch screed. It should leave me with enough space for a tile. What I would like to know is if 30mm insulation would be ok as I don't have enough space for the 2 inch insultion.

While I am at it - I may as well get another problem off my chest. I have a leak in a bedroom wall underneath a window. We thought the problem was sorted when we patched up the corner of the window on teh external wall. Plenty of rain since ans all was well. Had a look at the wall yesterday afet the heavy rain on Saturday and the wall and floor has a massive damp patch. Total heatbreaker. Any ideas anyone?? The internal wall is plastered and I'll be annoyed if I have to rip the plaster and dry ling down again.

Thanks in advance
POC
 
In relation to the floor, I would say that if its just in the hallway area, the 30mm insulation would be sufficient (assuming that you're not going with underfloor heating.)
You need the 3'' if screed to ensure that it is strong enough, but then again, the tile on top will be taking most of the pressure.
But it looks like you have to reduce either the insulation or the screed, I'd reduce the insulation, if only in that particular area.
Although a two inch screed covered with a tile may not be a bad option either.
As for the damp patch, you seem to have looked at the problem being water coming in somewhere around the window, which you thought you had sorted out, but it's back again, frustrating alright.
Could it be that your damp proof course is compromised under this part of the wall, or is moisture finding its way in through the ground?
Otherwise I suppose its just a case of looking around the window again if you're convinced that there lies the problem, and resealing it all around.
 
30mm insulation will not meet building regulations.....
assuming you have 5 inches (125mm) to play with...
75mm PUR insulation (TC value of 0.023)... this will meet regs..
then pour a 40mm ash self levelling screed (easy screed or similar... reinforced with 304 mesh)
that leaves you with 10mm for a floor covering... but you can also get a door made to suitm which would be a better option, then pour 50mm screed....
 
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