Laying loft boards over insulation

[MDandM]

I have just had my loft insulated to current standards. I now want to put items back in the loft for storage. I know which way the joists run but due to the thickness of the insulation I cannot secure the new loft borads to the joists.
Is it OK to lay these boards over the insulation to allow me to walk on the loft boards and store the usual bits of old furniture, christmas decorations and childrens cot (just in case we ever have grand children that come to stay).
I am looking to use 8ft x 2ft tounge and groove loft boards and lock these all together with a batten running round the edge of the total area of approx 12 x 18 feet.
Any advice and suggestions gratefully received.

PS I know that I can get an 8x2 loft board into the area.

 

[Static]

Counter batten the joists with new timbers running at 90deg to the depth of the insulation and then board to these.. adds a little extra extra dead load but not enough to worry about..

 

[MDandM]

Thanks for the information Static. Unfortunately that would mean removing all the insulation and adding the cross battons to the existing joists.
Is there an alternative?

 

[doni]

Bit confused here - if the loft insulation is just sticking out from between the joists and you lay the T&G at 90 degrees, wont it just compress the insulation, and you can then screw the T&G down? You are not suggesting laying the T&G in the same direction as the joists are you?

 

[MDandM]

The loft insulation now stands about 12 inches higher than the 4x 2 joists. The joists run north to south and the first layer of insulation which was pre existing runs between the joists. The installers have now instaled two layers one runnning east west and the top layer running north south. Therefore if I was to cross batten the joists I would first of all have to take up the two layers of insulation, then put in the cross battens and then relay the insulation. At this stage I would then be able to put in the loft boards.
Any suggestions as all I want to do is put in a surface that will allow me to store fairly light weight articles and be able to move around a small area of my loft.

 

[freddiemercurystwin]

Thanks for the information Static. Unfortunately that would mean removing all the insulation and adding the cross battons to the existing joists.
Is there an alternative?

Not really this is one of about 10 threads a month with the same query, all posters are advised this, there is no alternative.

 

[JoeAR]

Already had 100mm base layer of insulation which almost came to top of joists. Wanted to increase thickness of insulation and lay loft boards over the top.

I used two thicknesses of studwork timber (38 x 63 x 2400) on top of joists to raise the joist thickness. First, short lengths of timber (blocks each 10-20cm long at reasonable gaps) screwed onto joists; then full length timbers screwed on top of the blocks. This method automatically coped with cables/pipes that were in place over the existing joists.

Then I laid 150mm Knauf space blanket insulation (clean & easy to lay). This fitted nicely into the joist gap ( 2 x 63mm high) , over the existing insulation.

In those parts of the loft to be unboarded, I simply omitted the studwork timber. With care, the studwork timber can be added later if more boarding is needed.

At the time, Wickes were cheapest for these products.

 

[mointainwalker]

If you compress your250 mm (?) insulation to 100 mm, you will reduce the insulation efficiency to approx that of 100 mm, no matter what thickness you had before compression.

The only benefit is noise insulation, so take heart that you won't be disturbing "The Man who lives inthe Loft "

 

[freddiemercurystwin]

MW, Gazzabighammer is a spammer!

 

[mointainwalker]

Really ?

I was replying to the OP anyway.