how to install Loft conversion floor joists

[pradeep39]

Hello all.

I am currently part way through a loft conversion with the works at the floor joist installation stage, I am using a building company for this.

The carpenters have fitted about half the floor joists now but some of the joists are sitting on top of the old joists and some have been fitted along side the old ones with about 50mm height difference from the bottom. I had the stairs fitted my some one independent about a year ago and the joists for that are paired up along side the old ones.

The way the new joists have been fitted means that the ceiling height will only be about 6'6"

Could some one tell me the correct way the joists should be fitted?

Thank you in advance

P

 

[freddiemercurystwin]

What do the drawings show? Doing this under Building Regs?

You often have lower ceiling heights in loft conversions.

 

[pradeep39]

Hi thanks for the reply.

Everything has been approved by building regs. The thing is that the joists that have been fitted are at differing heights. I spoke with the project manager and he assured me that it will come correct in the end. I'm not sure what the building regs say on this but would it be incorrect to install the joists lower down, therefore, affording a taller ceiling?


P

 

[tony1851]

When height is limited in a loft conversion ( ie relatively low ridge) it is imperative to get the floor as low as possible. This can be done by such means as using shallower joists but spaced closer together. Also by fitting the joists between the existing ceiling joists where possible, so that some of the depth of the new joists is sunk below the tops of the ceiling joists.
Remember that you will loose some height at ceiling level because of the insulation you need to pack in.
Make sure the builder is fully aware of your concerns before it goes too far.

 

[pradeep39]

Thank you very much for that Tony. I will have a chat with them on Monday

 

[stuartturbo]

Also by fitting the joists between the existing ceiling joists where possible, so that some of the depth of the new joists is sunk below the tops of the ceiling joists.
Remember that you will loose some height at ceiling level because of the insulation you need to pack in.

Im doing everything! my joists are on a small packer between old joists means about 3" higher.
as for insulation I am using 96mm tr31 on the flat roof and 25 inbetween rather than the 115mm. The flat roof i have got the angle from the beam rather than starting big and cutting down, just to get that little extra head room

 

[pradeep39]

Thank u I'll remember that for the next project