Boarding Out A Loft What is the Best Method/cheapest To Use?

divecomuk

Hi All,
I’m currently in the process of purchasing a relatively new house (built 2002), and would like to board the loft out.
This is just for light storage, usual Christmas decorations and so on. My question is what is the recommended method to
Use, as the insulation protrudes above the joists. So far I’ve seen methods using plastic stilts, adding more joists, specialist kits (very expensive)
and so on. So at the moment I really don’t know which way to go? I guess when it comes to the boards, the loft panels you can get from the diy chains are ok? Or is there a better and cheaper alternative?


Thanks In Advance

Divecomuk

jk0

I'd suggest these boards:

http://www.wickes.co.uk/Wickes-Chipboard-Loft-Panels-Pack-3/p/116420

and these legs: http://www.wickes.co.uk/Loftleg-175mm-Loft-Legs-Pack-12/p/100412

I haven't used the legs, but I have used the boards to make a temporary work platform while tiling above a bath. They are very strong when fastened together.

Edit: You might want to buy some spare timber for reinforcing the joints if your loft timbers are an unusual spacing.

phil24_7

Don't underestimate the weight of the loft boards. Most loft spaces are not up to storing much as the joist are only spec'd to hold up a ceiling.

I would personally strengthen these before doing anything (glue and screw joist to the tops of the current joists or add more joist across the current joists).

Regards
Phil

TheCyclingProgrammer

phil24_7 wrote: »

I would personally strengthen these before doing anything (glue and screw joist to the tops of the current joists or add more joist across the current joists).

I could be wrong, but I thought putting cross-battens across the existing joists would only improve the rigidity of the floor whilst doing nothing to strengthen the existing joists. To strengthen them you need to do the first thing you said. Its a good point though, especially if its a modern house with truss roof design (unless you have attic trusses).

I boarded a small section of our loft - I did use cross battens (we only have about 100mm of insulation and unlikely to top it up due to skeilings which makes things very awkward) mainly because our 1930s house has very irregularly spaced joists. Adding cross battens at consistent centres made the job much easier and helps spread the load,allow for some cross ventilation and to keep clear of the lighting wiring up there (remember to leave access to any junction boxes when fitting the boards - mark the boards and cut the tongue off that section so you can easily unsure and lift the board).

If had more insulation up there and more space I would consider the LoftZone kits.

phil24_7

Cross joisting does help to spread any load across more joists but if going to this amount of effort, the first option is preferred as it's not a lot more effort but you get the added benefit of the joist gaining most of the properties of a joist of the final depth! If that make sense?!?!

divecomuk

Hi All,
So it seems the recommend method is to reinforce the existing joists in the same direction. Then add another set of joists across those at right angles to give the
Required height, hopefully I’ve understood this correctly?
The additional joists do they have to span the entire roof space to spread the load. Or it ok just cover the area to be boarded with just a bit over each side?


Thanks In Advance.

Divecomuk

zaax

There should be 270mm of insulation up there, so the space it not really useable. Buy a shed

phil24_7

divecomuk wrote: »

Hi All,
So it seems the recommend method is to reinforce the existing joists in the same direction. Then add another set of joists across those at right angles to give the
Required height, hopefully I’ve understood this correctly?
The additional joists do they have to span the entire roof space to spread the load. Or it ok just cover the area to be boarded with just a bit over each side?


Thanks In Advance.

Divecomuk

You need to workout what size joist you need for the joist span then use construction glue (expanding wood glue similar to gorilla glue) as well as decent screws at regular intervals (I'd probably go for 400mm spacings) to screw additional joist to the top of the current ones to bring them up to that height. Then use joist across those take the total height to 270-300mm above the ceiling to give you enough room for your insulation. You could then run roofing batten in the same direction as your original joists to give you a nice channel for electrics, though this isn't 100% necessary as long as the wiring sits on top of the insulation.

Regards

phil24_7

zaax wrote: »

There should be 270mm of insulation up there, so the space it not really useable. Buy a shed

Why does 27cm of insulation make the loft unusable?

divecomuk

Thanks Phil24_7 looks like I’ve got a plan now! Just wanted to check what you mean about “You need to work out what size joist you need for the joist span”.
Will the new joists have to span the entire roof, which I assume would be the case? Or can you get away with just the area to be boarded? When it comes
to screwing the new joists to the existing ones. Would you do that directly through the joists, or use some type of stretcher plate?

phil24_7

There are span tables for floor joists. You need to measure the distance between the 2 walls that the joists span as well as the joist spacing, then cross reference to see the depth of the joist needed.

The added joists would need to span the entire length of the original joist and you would screw down through the top of it using screws that should penetrate at least half of the original joist (5x200's would fit the bill if the original joist is 10mm and the required thickness is 250mm). Don't forget to use proper construction glue, it will expand slightly to fill any gaps and will probably ooze out the sides a bit. Don't worry, this is perfectly normal and can be knocked off after should you desire!