Boarding a loft.

[lurker]

I plan to board out a bungalow loft.
This will be storage / “office space. It will not be a true habitable space, access via a posh loft ladder.

As I have already removed the chimney the majority of loft is unobstructed.
I think it will be around 9 x 9 metres of useable floor.

I was thinking of using osb sheet which I can get up there at the moment due to no ceilings in 50% of the house.
any opinions on my choice of floor?

 

[novocaine]

Whatss the cost difference with chipboard floor?
I found that osb sags between 16" joists.

 

[lurker]

Whatss the cost difference with chipboard floor?
I found that osb sags between 16" joists.

Not look at costs yet.
I was thinking osb was a bit lighter than chipboard, but I had not realised it might sag.

 

[That would work]

Also, chipboard flooring comes in 600 widths which must be easier. If you used osb would you not find yourself adding support where the boards butted up? if they did not land on a joist that is. The flooring chipboard will be T&G already so this wont be a problem.

 

[AndyT]

There's a special lighter weight grade of chipboard for lofts. It avoids two possible problems by putting less load on lightweight ceiling joists and by being not too heavy to thread through a loft hatch and move into an awkward position.

 

[Doug B]

You could go for flooring grade t&g OSB which is slightly lighter than its chipboard equivalent

 

[jonbee56]

Don't forget to screw the boards down... If you start hammering nails into the joists, there's a good chance some of the plasterboard ceilings will pop

 

[MikeG.]

Access is always the issue when boarding a loft. An 8x4 sheet won't fit through a hatch, but even the loft sheets (8x2 feet) often don't because of the engle they have to go up and the consequent fouling of roof timbers. My suggestion would be t&g loft boards (2400x600, as I said). There is also a 1220 x 320 size. All boards are in either 18 or 22mm thicknesses, and you'll definitely need the latter if your timbers are at 600 centres.

Don't forget you mustn't compress insulation, and with the requirements these days (you should have at least 230mm up there) you may well need to build up some secondary timbers to support the new floor. If you haven't got 230mm, now is the time to put the extra in.

 

[worn thumbs]

I found the chipboard sheets with the bevelled T&G edges were a quick and easy way to do the job.When I boarded my loft about thirty years ago,the insulation requirements weren't as stringent.I do wonder whether the conductivity of OSB or chipboard might be comparable with rockwool.You should definitely use screws to hold the boards down and don't forget to bring out any electrical cables before getting too far into the job because you are likely to need lights and sockets up there. I put a light and switch in the loft and made sure it was in series with the light down below so that the light in the spare bedroom had to be switched on to allow the loft light to work.Conversely,I couldn't leave the loft light on for months without switching the spare bedroom light on as well-and I wasn't likely to do that.

 

[Phil Pascoe]

Don't forget to screw the boards down... If you start hammering nails into the joists, there's a good chance some of the plasterboard ceilings will pop

Does anyone hammer anything any more?

 

[Phil Pascoe]

I was thinking of using osb sheet which I can get up there at the moment due to no ceilings in 50% of the house.
any opinions on my choice of floor?

Don't forget you still have manoeuvre it when it's up there.

 

[lurker]

Thanks for the suggestions, food for thought.
Will check the joists centres.
I realise that the insulation might get a bit compressed but it is a downside I am prepared to tolerate.
Later when I have more time,I might add further insulation underneath the roof itself as is done for proper habitable rooms in lofts.
I wanted to avoid t & g incase I needed to lift boards to access lights wiring etc.
At the moment I can get big sheets up there and assumed that with less joints I would need less fixing screws , but the overall structure would be firmer.

The roof resembles an A shape with walls either end. What type of roof is it called?

 

[Doug B]

The roof resembles an A shape with walls either end. What type of roof is it called?

Gable ended roof .

 

[Cheshirechappie]

Does anyone hammer anything any more?

There are some who hammer dubious debating points on off-topic board threads!

(Not this thread, which has been quite helpful and informative.)

 

[lurker]

Been measuring. I am restricted as to when I can get in as I have builders there.
Joist centres are 450mm.
As I will keep the floor a reasonable distance from the eves. My total floor area is 9 x5 metres.

 

[Racers]

Sounds big enough for a loft conversion...


Pete

 

[lurker]

Sounds big enough for a loft conversion...


Pete

Yes it is and some neighbours have done so.
BUT if it’s a nice accessible room, her majesty will requisition it.
This way I have storage for my fishing tackle, books, photography kit etc etc