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2" Studs on Concrete and Mouldy Chipboard - Any Health Issue?

Postby oxfordite » Wed Mar 05, 2014 6:42 pm

So much trouble in just one room! Smell of mould/mildew; carpet and underlay removed.

A flat-roof (roofing felt) single storey extension, 35yrs old, gasCH (large rad)
To one side, exterior brick wall of cavity wall is wall of garage
Injected foam cavity insulation ~1980s
concrete subfloor - no air brick vents
2" stud work (optimistically) sat on small pieces of roofing felt
20mm chipboard nailed on top
Smell of mould/mildew!

SW facing - lots of rain ingress since start of rain in December.
Ivy had wrapped around gutter, bargeboard, under roof felt, etc.
corrugated garage roof cement fillet had failed too...
...ivy is removed, guttering replaced, plastic facia, 6" flashing now covers brickwork beneath facia and edge of corrugated roof: water ingress is halted.
2 fan heaters are heating the garage wall
I intend drilling a vertical series of holes through that brickwork in the garage to drain/vent the moist cavity and speed drying.

Stripped wallpaper
Behind lining paper, one area of plaster was water saturated - and I found various hidden patches of black mould.

Lifting chipboard I find varied colours of mould - green, yellow, brown - on 2" timbers, and same on underside of chipboard.

Do I need to remove ONLY the timber with visible mould?
ie. nearest the water ingress?
What should I treat the concrete floor with?
Do I need to treat all remaining timber? Underside of old chipboard?

How far do I need to go to see a safely habitable environment?
- air bricks to somehow vent that tiny 2" void?!
- mould killing treatment if so which ones?
- dispose how much timber?
- where to insert a DPC plastic sheet: above or below the chipboard?
- should I seal the concrete subfloor?
- should the room have a slip-slide wall vent at low level?
The plan is to lay laminate flooring on Wickes green 3mm underlay...
...a nice simple DIY task to eliminate an old smelly carpet, or so I had thought!!
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Simply Build It

Postby welsh brickie » Thu Mar 06, 2014 4:33 pm

remove all the timber and chipboard, paint the wall and floor with a buitumin paint, basically tanking the room, Refit new pressure treated timber, and insulate with 50mm kingspan, or similar insulation board,plasterboard and plaster to finish,install airbrick.
welsh brickie
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