Loft Flooring Making Good

[bbru]

Hi loft fans --

My mate and I have boarded my loft using standard B&Q boarding. With non-standard widths between joists, we simply got them all down without cutting and one consequence is that there are some ends that hang between joists. We assumed that surrounding boards would hold it together, but have found that even reasonable pressure will flex and break the boards.

Having spent a couple of days on this we need to get a way of correcting the problem. My question for the board is this -- would it be a better use of time and money to board over it with lighter board (say 3-5mm ply), or unscrew the whole lot and start again?

Any advice/insight appreciated.

Regards

Ben

 

[JohnD]

if you have already spent a lot of money on loft floor panels (and that is an expensive way to do it) then I would suggest counter-battening.

Take up the panels carefully so you can re-use them. I hope you used screws not nails. Chipboard is inclined to splinter so always drill and countersink first.

What you do is put lengths of 50x100mm (or 50mm sq would do) across the existing loft timbers, but at right angles to them, at a spacing which allows you to have a batten under each end of each board, and in the middle.

If you screw the battens down firmly, they will make the floor more rigid as the spread your weight across several timbers while you are clambering about. However they do not make it overall any stronger, so you can't treat it as a habitable room or put a piano up there.

It might be useful to know the dimensions and spacing of the existing timbers, and have some photos to show how it is built.

BTW experiment and see if you can get a standard 8ftx2ft flooring chipboard through the loft hatch, if so it is a much cheaper way to do it, with fewer joints. Ply is lighter and stronger.

 

[bbru]

John: thanks for the quick reply and for not stating the obvious about the ends of the panels and joists matching!

I've collected the additional information...currently boarded area is 1.88m x 7.67m. Something 2' wide will pass through the hatch, but not really to the full 1.88m extent. Image appended...

Untitled

• bbru
• 10 May 2009
• 1

I've thought about your suggestions, and think the time is more important than money: I have hospital treatment coming up and need it done!

Considering the first layer of boarding is adding some rigidity to the floor, would it be possible to simply overboard the whole lot with sheet material. The sizes indicate I'd have to have to use a single 8' long board (cut to 1.88m) by 7 of 4' wide boards cut to 2'.

Question is what material to use? Might 18mm or 12mm chipboard work; or would I have to go for 9.5mm ply. Costs would range then between £90.16 for 9.5mm ply and £70.42. I imagine the extra £20 would offer a lot more support.

Any more pointers, anyone?

Thanks

Ben

 

[Symptoms]

bru - 'cos time is your driving force the quickest method is to overboard in ply - the thickness of which will be determined by the use you intend putting the loft to ... hydroponics or suitcase & Xmas decoration storage. Storage - use the 9.5; dope-growing beef up the whole roof structure The extra weight (not that much) of the ply isn't going to affect structure IMO.

For future reference & for other viewers, if you lay this chipboard stuff cut the ends so they rest on the joists (yep, you'll lose a bit of material but will reduce problems). You can't rely on tongue & groove ends of this stuff to to support much weight. And always use screws ... hammering-in nails might affect the plaster ceiling below (cracks).

 

[HELPMABOAB]

Hi John D
You say that is an expensive way to do it(Using panels).
Can you advise please,which is the most economical way to do it.
Thx.
Eric

 

[JohnD]

buy flooring in 8x4 or 8x2 sheets and cut it to fit

far cheaper than using tiny panels, and stronger as fewer joints
I can just manage to lift an 8x2 into my loft

 

[HELPMABOAB]

Thank You JohnD
Good suggestion.
There is actually a company just started in my area offering.
Loft Flooring.
Loft Insulating.
Loft Electrics &
Loft ladders.
All fitted and guaranteed.

Mind you,I dont know what sort of money they are talking about,but I spose its an underused area if its not floored out?

Your thoughts(Anyone).

Eric

 

[bbru]

Hello all --

I thought I should update you...and hopefully help anyone else looking at this page. We boarded over the first layer of boards in the opposite direction and this made the floor sturdy. Great!

A few weeks later -- and without anything heavy being added to the loft -- cracks began to appear at the edges of the rooms below. Where the ceiling joined the outside wall of the house; and also where the internal partition meets the outside wall. This also happened on other rooms connecting with the outside wall.

So, having a new son in one of the rooms, we called a surveyor. Here's what he said (hoping to avoid anyone else shelling out!)
-- 1. The roof construction should allow for around 5kg/sq.m. across the surface of the loft. Of course, you'll need to deduct the weight of the board. The problem does not affect the safety of the house, or what another survey would report to a buyer
-- 2. The roof should be constructed with ties to attach the structure of the roof firmly to the gable ends of the house. In my case, there are not enough of these. I have to buy BAT straps and place them at 900mm intervals -- attaching these to both the roof or floor, and the gable end. Where the roof does not butt up against the gable end, then this must be packed. Where these are attached to the roof, a noggin must be installed
-- 3. This slight movement of the roof has moved the boarding and so the ceiling downstairs. This has caused the majority of the cracking.
-- 4. The other cracks are simply because of moving around in the loft and the very poor quality plastering. There are no tapes on adjoining plaster boards

It's up to me now to pack the roof, install the straps and noggins. I just hope this stops anyone else going through the same thing.

PS: The house is 1980-constructed detached.