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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Extending back of house to build kitchen https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1118166531 Message started by Ian_Reynolds on Jun 7^th, 2005, 6:48pm

Title: Extending back of house to build kitchen
Post by Ian_Reynolds on Jun 7^th, 2005, 6:48pm

Currently have a toughened glass lean-to at rear of house spanning width of house and going out 5 ft. It's come down and been extended out 3 metres from rear of property in blockwork (converted into kitchen one side and living area the other side).

The floor of lean-to is 15 inches lower than the house floor level, below air bricks, below damp course of existing house floor level, has a 1 inch/2 inch concrete floor screed on it and houses a main drain manhole in middle.

I'm building a suspended floor on brick supports with floor joists and board to bring floor level up to existing house floor level but would the cement floor of the lean-to be ok to house this or would it need demolishing and hardcoring/insulating?

Thanks

Title: Re: Extending back of house to build kitchen
Post by JerryD on Jun 7^th, 2005, 8:36pm

Do you not have building regs approval for this job?

If you have, the drawings will show what is required.

Why do you need to support the new floor joists on the old concrete floor, the joists should go into the walls of the building (with new 'joist seals' fitted)

If mid-span support is needed (a vented sleeper wall) then presumably the old outer wall of the lean-to wold be adequate for this? Only a site inspection can determine whether this is adequate though.

What's going on the 'oversite' of the new bit? i.e. the additional 2.5 metres past the old lean-to.

Joists will need a 175mm air gap under them.

On ground floor suspended floors, insulation is placed between the (treated) joists, NOT under them.

Your regs approved drawings will show what insulation the council require, usually 130mm Celotex or equivalent.