How to board a loft

[Geege]

I'm thinking of boarding my loft for general storage and I'm looking for advice on how to best approach the task. I've read up quite a bit and I think I have an idea of what I should do.

• I have a Trussed Rafter type loft in a new build terraced house (2004).
  
• My loft hatch is a standard uPVC which is about 620mm x 520mm in size.
  
• The current joists measure about 35mm thick x 96mm tall and are spaced about 560mm apart.
  
• I have some plumbing in the loft (not much, my control unit just for my Triton Digital Shower) and three up-lighters from the bathroom.
  
• I have some electrical cables, sky satellite cable and mains cable that runs over some joists.

I'm thinking of screwing timber at 90 degrees to the existing joists to raise the floor a little to allow clearance. I do not want to cut grooves into the existing joists as I understand this may weaken them. What should I use, treated timber, stud partition timber?

Then I'm thinking of laying floor boards on top of that, thinking about moisture resistant chipboard 22mm thick (green board) Tongue & groove, for example what Wickes sell.

There seems to be sufficient loft insulation already, but I guess I could top it up a bit.

Any suggestions as what I should consider?

 

[paulyoung666]

to do the job properly you need to suspend the new floor away from the old floor .......

 

[Sonic67]

If you were boarding the loft to use as living space then you need to strengthen the joists as they aren’t designed to be walked on. If you are just creating storage space then it’s up to you. Bear in mind some things might be iffy. Your lighting cables should be already being run above the insulation. If they end up enclosed it’s not so good for them.

 

[FruitBat]

I looked at the Wickes chipboard loft flooring and I thought it was too heavy. Plywood is lighter and (I think) stronger. I ended up getting 18mm plywood from my local timber yard (I think they called it shuttering ply - good enough if you're just using your loft for storage). The plywood comes in 2440 x 1220mm sheets, so I got them to cut it into 3 long strips (2440 x 400mm approx) so that they could go through the hatch. Once in the loft it's a doodle to cut them to length. I used screws rather than nails to avoid any damage to ceilings (old house).

 

[shoemaker666]

the realy simple way which is what i did is to lay celotex sheets on top of exiting joists insulation everything. then just lay chip board ontop. tripled me insulation now got over 16inches insulation. and nice level floor no extra wood no screwing simple

 

[Cliff]

So what is the proper way to put boarding in the loft? Can the insulation be left between the ceiling and the new boarding? Can the wires be left as they are- just on top of the ceiling plaster board.
Any regs on this?
Just asking, not for making the loft into a room, just for clambering around without putting your feet through the ceiling.

 

[mjn]

I just used chipboard loft boards, didn't screw anything in, just cut to size, to make sure of snug fit.

 

[brumhee]

I have a similar type roof and when I was looking there are pedestals you can use which sit on the joists and you fix the boards on top.

As the boards are sat over the top it doesn't squash the lagging meaning the insulation is not reduced.

Found these doing a google search http://www.toolstation.com/shop/Con...k/Loft+Flooring+Legs+175mm/d210/sd2797/p44016

 

[monkey_boy69]

I'm thinking of screwing timber at 90 degrees to the existing joists to raise the floor a little to allow clearance. I do not want to cut grooves into the existing joists as I understand this may weaken them. What should I use, treated timber, stud partition timber?

Don't screw timber 90 degrees to the current joists. That won't add strength. You have to put timber in line with your current joists from end to end or from end to supporting middle wall. I've done this before and got 3x2 joists and bonded & screwed the joists to the top of the others (ask any builder and he will tell you this is the correct way unless you are wanting to turn this area into proper living space (if so then you'll need to get it all done though planning permissions etc)). Use PU glue and get some 100x6mm screws. Pre-drill the new wood then bond then screw these to the current joists.
You don't want to get this wrong as if you do you'll either cause the ceilings to sag or at worst come though the ceiling!

 

[whatsupdoc]

I used that Wickes chipboard flooring several years ago and it's done the job perfectly, and cheaply.
.
.

 

[Geege]

Thanks for everyone's advice.

So monkey_boy69 - do you mean screw timber bits adjacent / side by side to the current joists?

I want to ideally add strength without adding steel beems, so that I can at least walk around in the loft to shift boxes for storage. I want it to take my weight.

 

[Geege]

I used that Wickes chipboard flooring several years ago and it's done the job perfectly, and cheaply.
.
.

Was that directly on top of the existing ceiling joists?

 

[russ123]

I've used the tongue and groove chipboard loft boards twice before without issue. Just screwed directly to joists at 90 degrees. Just doing it to aid storage.
I'm no sparkie but can't see why encasing cables is an issue as surely they are between ground and first floor in pretty much the same way bar the insulation which should be fireproof?
One word of warning is it is harder work than you may think. You need to consider you need to cut the boards so the joints line up with the rafters with half a rafter for each board. You can't just butt them up against each other over a gap as they are liable to snap when trod on. It can also get VERY hot in lofts this time of year so maybe wait 'til it is colder.

Edit, just saw that you mention it is a new build whereas I've done it in in 100 year old properties so the my rafters may be a lot stronger. As I walked on mine before straddling them I was not concerned about adding strength.

 

[WeegyAVLover]

Geege...

Hope you do not mind me hijacking this thread with a few of my own questions.

I have an old Victorian Terraced house. The loft I have is big area, however it has the insulation policies of a meat popsicle (this is not a compliment to my loft!).

My current rafters are 100mm deep, so can take 100m insulation. However I want to lay another layer of insulation that is 250mm taking it up the minimum standard. However, like the OP, I want to be able to walk around my loft so need to floor it.

Again, like the OP, I had thought of buying planks/beams of wood that were 175mm deep to run at 90 deg to rafters. The loft currently has loft boards over all the loft so there is no additional cost or load there but would be if I added the insulation and, more importantly, the beams of wood.

My questions are what type of wood should I be looking at? Treated CLS?

Should I worry about the additional weight these beams will put in my loft?

 

[Kebabhead]

However I want to lay another layer of insulation that is 250mm taking it up the minimum standard. However, like the OP, I want to be able to walk around my loft so need to floor it.

My questions are what type of wood should I be looking at? Treated CLS?

Board the loft out and put the insulation on top of the boarding

You don't need any type of special wood those chipboard loft packs are sufficient

 

[Curry Monster]

Board the loft out and put the insulation on top of the boarding

You don't need any type of special wood those chipboard loft packs are sufficient

I am currently in the middle of doing my loft with the packs from wickes - the fact they interlock into each other makes for a quick installation... I have not tried to cover every small amount of space just the large areas so I can store xmas decorations and cases etc.

Its a horrible job - wear a mask if you have insulation and try and do on a cool day - I was fitting some last week and it was like a sauna up there!

 

[WeegyAVLover]

Board the loft out and put the insulation on top of the boarding

You don't need any type of special wood those chipboard loft packs are sufficient

Thanks Kebabhead but I am not sure I understand you correctly.

I currently have loft boards on top of my 100mm joists.
My plan was:

1) Lift loft boards.
2) Lay 100mm insulation between joists.
3) Lay Joists at 90 degrees to original.
4) Lay 150mm insulation between new joists.
5) Lay loft boards back down.

This way I will be able use it as a storage area for cases, xmas decs, small children & a portal to the realm of the undead (not sure where that came from!).

If I lay insulation on top of the boarding my assumption is that will stop me being able to use the loft as a storage area - have I understood you correctly?

 

[IronGiant]

You have understood him

I don't think he understands what you want to do.

Which is use your loft after you've insulated it.

Some people on here have looked into using loft legs, but I don't know if anyone went for them:

Loftleg ? Energy Efficient Loft Storage is one example

HTH

 

[Geege]

No worries WeegieAVLover - the more input the merrier!

Here are some photos of my loft - New build with trussed Rafter type loft. As you can see it has ceiling joists and that horrible itchy insulation. There are also some planks of wood braced against the wall with metal.

I was also thinking of using Treated CLS or similar for the supporting batten at 90 degrees to the current ceiling joists, and then lay Wickes 22mm interlocking T&G green board on top. (My joists are 560mm apart)

T & G Chipboard Flooring 22x600x2400mm - TG Chipboard Flooring - Sheet Materials -Building Materials - Wickes

But surely this must be quite heavy? What else can I do to support the ceiling joists as I don't intend to use any steal beams.

I also have a few obstacles too, including the plumbing pipe for the Triton control unit for the shower and also the shower extractor fan.

As you can see much of the grey mains electricity leads are pinned to joists or run over them. (That black cable is the Sky lead).

 

[IronGiant]

Those legs may suit you too Geege

 

[WeegyAVLover]

You have understood him

I don't think he understands what you want to do.

Which is use your loft after you've insulated it.

Some people on here have looked into using loft legs, but I don't know if anyone went for them:

Loftleg ? Energy Efficient Loft Storage is one example

HTH

I have seen these but heard mixed things about them breaking. Wood would probably work out more expensive but would be solid and no danger of breaking... Or at least not as much as plastic legs.

 

[IronGiant]

Fair point, I was wondering how strong they actually are, although you would think that if they were installed at the recommended intervals they would be OK.

 

[shoemaker666]

i have mentioned this before but will do so again. the way i have done it is so easy use sheets of celotex insulation straight over the top of existing joists and insulation etc. then put the boarding over the top of that. the celotex is surprisingly strong and will take your weight while crawling about. now i have a nice even floor 4 inches of normal insulation. and 4 inchs of celotex (which is equal to 8 inchs of rock wool).

yes celotex is more expensive than rock wool but no need to lay extra timber so the cost equals out and this way is alot easier

 

[WeegyAVLover]

Fair point, I was wondering how strong they actually are, although you would think that if they were installed at the recommended intervals they would be OK.

Agreed, I also give no guarantees that the people complaining about them put them at the correct intervals, so they maybe okay.

If I am honest I am not planning on having my loft like Anneka's Midden so they might work.

Geege - One thing I want to ask to avoid oversights, will those boards fit through your loft hatch? I know on newer builds hatches are not always the biggest gaps in the world.... Don't want any Homer Simpson moments

Its not cheap being efficient is it!

 

[Geege]

As much as I like the idea of the loft legs I too had wondered how strong they would be to cope with the weight of 22mm thick boards and my weight and stored boxes. So using cross 90 degree battens with T&G loft boards it is then I think. I trust this would be strong enough? Surely it would distribute the load more evenly than I am doing at the moment.