Loft boarding for storage advice

ubay25

Hi, I live in a quite new house (3 years old) and just thought of making our loft more usable. As you all know new houses today are not that generous with spaces so I need to find space for my light junk.

I climbed up my loft today and saw some potential however I have a few questions which I hope you can help me with before I start this small project.

The joist is 40x70mm and the width between joists is around 400mm. The insulation thickness complies with the building reg of 270mm.

Links to pictures I have taken in the loft: (copy and paste in browser)
hh-roadways.co.uk/img/loft1.jpg
hh-roadways.co.uk/img/loft2.jpg

Questions:
1. Are the joists strong enough for boarding to support additional load?

2. What do I do with the insulation because if I lay the boards, some of the insulation will need to be removed. Obviously it will not comply anymore with the 270mm insulation thickness.

Thank you in advance.

WestonDave

70mm joists are thinner than the old 100mm ones but should still be OK for well distributed light storage - probably not suitable for loft conversion.

You have 3 options.

1. Extend the height of the joists by adding more timber to the top of them (generally advisable to go across the existing ones so you can insulate across them rather than leaving cold spots). This means you can fit the full depth of insulation underneath the boards. However this is likely to be hard going.

2. Remove the excess insulation and use the insulated boards that B&Q sell - http://www.diy.com/diy/jsp/bq/nav.jsp?isSearch=true&fh_search=insulated+loft+boards&x=0&y=0

3. Remove the excess insulation, use 2 layers of space boards and then board over the top. http://www.diy.com/diy/jsp/bq/nav.jsp?isSearch=true&fh_search=space+board&x=0&y=0 I think from memory each pack contains more than one board but you'll need to check this.

You'll need to work out which gives the best insulation and works out cheapest bearing in mind with the latter you will need to buy boards as well. We went with the space board solution which was very easy to work with (you can cut them with a carving knife!) as the other option wasn't available at the time. At the time Focus was doing some kind of deal on them so check all the options for who has the best prices!

One tip - if you buy the loft boards seperately get them all from one place - there are at least two join patterns around which are incompatible with each other so you can't mix and match.

WestonDave

Oh - and if you do end up removing insulation - shove it in the areas you aren't boarding to add insulation - just be careful not to shove it too far into the edges so you maintain air flow otherwise you will get condensation up there.

dander

Hi Dave, I've never seen those boards before - can you tell me how they're fitted? Presumably you don't screw them down to the joists like normal boards? Or do you, but using really long screws?

ubay25

Hi Dave,

Thank you very much for your advice, it opened up a whole lot of options. I appreciate it.

The 3rd option looks more desirable but also my question would be the same as Dander's. How do you exactly fit them?

Thank you for your help so far.

Gloomendoom

When I did it I increased the depth of the joists up to 12" and laid standard 8 by 2 chipboard flooring sheets on top.

It took absolutely ages but I did end up with a solid floor that can be walked on.

p.s. If you are going to do it, get it done before the weather warms up.

ubay25

When I did it I increased the depth of the joists up to 12"

Is this 12inches or 12cm?

Gloomendoom

ubay25 wrote: »

When I did it I increased the depth of the joists up to 12"

Is this 12inches or 12cm?

Yes, 12 inches, 1 foot, 305mm.

WestonDave

OK - sorry off air for a while.

Spaceboards just lie "loose" across (i.e at right angles to) the joists - they are strong enough to take your weight but will mark/dent hence the boards over the top. Its best to stagger lengthways if you can but this depends a bit how regular your joists are! Because of the nature of the material they will stay put pretty well during insulation as they don't slide on each other.

The loft boards that go over the top interlock on the long edges so provided again that you stagger them you end up with a fairly tight stable platform, at which point realistically you only need to put a few long screws through the edge boards to hole the whole lot in place.

One thing to bear in mind is that if you are doing the area around the loft hatch, you will end up with a thick entrance hole that you may want to strengthen by adding timber to the thickness of the space boards and then you can screw the wood panels there again as a fixing point. This isn't hard - its basically a case of cutting 4 pieces of the relevant sized timber to form a square or rectangle and then fixing it to the existing loft hatch surround.

In terms of screwing it down, you'll need to know where the original joists are, but this is normally easy enough to work out from the edges - watch out if you have any funny staggers in the middle. Then get a small pack of long self tapping screws, drill a suitable hole through the top wood, and just screw it into the joist - an electric screwdriver or slow speed drill with screwdriver bit helps here. It saves having to drill a deep hole all the way down.

Dander - its not clear whether you mean the space boards or the all in one boards - we didn't use the all in ones, but I would imagine you do screw these down with long screws, but again I would think that by the time you have interlocked them all, you only really need to screw the edge ones to stop them drifting apart.

WestonDave

Oh and as Gloomendoom says - don't save this for the warmer weather - any messing around in the loft is best done when its cold otherwise it gets sweaty, itchy and generally horrible.

tizerbelle

WestonDave wrote: »

Oh and as Gloomendoom says - don't save this for the warmer weather - any messing around in the loft is best done when its cold otherwise it gets sweaty, itchy and generally horrible.

Thanks for that explanation. As I read Gloomendoom's post about doing it now I assumed it was something to do with wood contracting/expanding in different temperatures - never occured to me it was just a "worker comfort" thing

You know, I really should check my loft out - been here over 2 years and never poked my head through the hatch - in fact - I'm off to have a look now.