Raising Joists to board loft

cubegame

At present a quarter of our loft is board and I want to complete the rest.

Unfortunately the previous occupier just stuck the boards on top of the joists and compressed all the insulation in the quarter that has been done.

I now want to board the rest and reinsulate. As I want to maintain the insulation this will mean raising the joists so I wanted opinions on the best way to do this.

I've seen you can get plastic stilts and obviously you can use timber. What are people's opinions on the merits/costs of each?

Cheers.

jc808

you can either put 200mm thick wooden battens along the existing joists and board on top of that, or the recommended way is to fit said battens perpendicular (across) the existing joists and board on top

youll find if you glue and screw everything together well, your loft floor will flex much much less (so no cracks in bedroom ceilings etc)

i would recommend hiring an impact driver and chopsaw for this job, ive done it in my loft and its the !!!!!!!!!!!

SailorSam

It's been done here.
http://www.diynot.com/forums/viewtopic.php?t=167959

fluffymuffy

Ceiling joists are not designed to carry the weight of battens, flooring and then whatever is stored on top once you have it looking like a real floor. It's not a floor. That would be carried by floor joists.

jc808

fluffymuffy wrote: »

Ceiling joists are not designed to carry the weight of battens, flooring and then whatever is stored on top once you have it looking like a real floor. It's not a floor. That would be carried by floor joists.

Presuming your only using said boarding for access to the loft (For things like maintenance etc) and light storage, you should be fine

ptkloon

jc808 wrote: »

Presuming your only using said boarding for access to the loft (For things like maintenance etc) and light storage, you should be fine

I was hoping to floor my loft and use it for light storage (xmas decorations etc)
Would I be ok just using chipboard across the original joists? The house is less than 20 years old and insulation is good with a small space between the top of the joists and the top of the insulation.

macman

Why is compressing the insulation unacceptable?

Happy-Days_3

macman wrote: »

Why is compressing the insulation unacceptable?

It reduces the effectiveness of it....

Happy-Days_3

We wanted same thing - well insulated, but loft boarded for storage.

Expensive option, but tidiest, replace insulation with celotex insulation. Will cost a lot, but then let you put boards at existing joist height. Plus messy as need to remove old insulation.

In the end, I cross battened our loft, so it was joists with insulation between them, then cross baten with insulation between them and them finally boards on top. Then used as storage.

Not a fun job, but all you need is wood, a saw, drill and screws...

In my profile is a link to my blog on our house. Have a look back to last year, nov, dec time I think. Thou can see how we did ours....

cubegame

Thanks for all the answers. In the end I did buy a load of celotex foam boards and that's a job for this weekend.

Keeps the weight down too as apart from an access plank I can board on top of the foam board with hardboard.

Happy-Days_3

cubegame wrote: »

Thanks for all the answers. In the end I did buy a load of celotex foam boards and that's a job for this weekend.

Keeps the weight down too as apart from an access plank I can board on top of the foam board with hardboard.

Worst part of the job will be getting rid of the old insulation. Put down a lot of sheeting. Get a lot of bin bags. Get gloves and masks - it really is nasty stuff. Enjoy!