Loft Conversion - Head Height

TheDirector

Hi,

We would like to convert our loft and just wondering how much space do the joists, floor and roof insulation plasterboard, floor add up to roughly (assuming joist go in between the the ceiling ones and thinner insulation used)?

Having measured the space from ceiling joist to bottom of ridge, there is currently about 215cm. So trying to work out what we will be left with - we are not too concerned with the ceiling being low to be honest (though would obviously would like to know), but need to work out if we will have the required height at top of stairs, which I believe needs to be 190cm.

Thanks.

theGrinch

That doesnt sound enough as is. You usually lose 60cm in the course of the work.

Rodders53

Google is your friend. Plenty of guides out there.

One I'll quote from says "Part K of the Building Regulations sets measures to prevent, falling, collisions and impact. This demands a minimum headroom of 2m in all escape routes, including the stairs. This head height can be reduced to 1.8m at the edges of a stairway if allowing for a sloping roof, as long as the centre of the flight is 2m."

You'll need to meet the current insulation standards, too.

You can read the regs for yourself https://www.planningportal.co.uk/info/200135/approved_documents

TheDirector

60cm wow. But Im not sure that is correct. Whilst I do not know for sure (hence me asking) from everything I have read it can be done a lot lower than that.

As for regs, yep I'm aware it is 2m and 1.9 as an absolute minimum, with 1.8 at the edge.

sevenhills

TheDirector wrote: »

60cm wow. But Im not sure that is correct. Whilst I do not know for sure (hence me asking) from everything I have read it can be done a lot lower than that.

As for regs, yep I'm aware it is 2m and 1.9 as an absolute minimum, with 1.8 at the edge.

I guess each conversion will be different.


If you look at the photo in the link, much of the insulation in the roof is in between the roof joists and it maybe could be done in a similar way on the floor.


https://www.thegreenage.co.uk/how-do-you-insulate-a-loft-conversion/

Doozergirl

It does vary, but for the roof you want 50mm air gap, 125mm solid insulation, 15mm plasterboard and skim. Your existing rafters will be included in that measurement.

The floor really varies according to the span and building method, but traditional joists are usually 7X2s ; so 175mm plus 22mm floorboards. Can be less. We're doing a little one with 4x3s. There are different ways of doing things so it needs to be talked through with the structural engineer.