loft insulation & cross battens

[bobby_la_mesma]

Hi

I want to increase the level of loft insulation from 100mm to 270mm. My joist are only 100mm high. I don't want to loose the timber as I need some of the space for light storage.

I've read on this site that I should cross batten the roof with a timber of 200 to 225 mm x 35 or 50mm.

This is probably a daft question, but what method should I apply to fix these to the existing beams i.e. nails, brackets, screws? What length of fixing should I use and lastly is it just a matter of screwing diagonally through the new beam and into the existing. I work in electronics so I don't have a clue

Thanks in advance


Rob

 

[Deluks]

Your idea of battens is slightly off.
9" timbers alongside existing is to strengthen the floor to make it habitable, these are sistered joists.
The batten idea shouldn't need any more than 3x2 (75x50mm ) these sit on top of existing joists at right angles to, to help spread the load for storage and light (trainset) use.

Don't nail, it will crack the plaster on ceilings below, better to pilot drill the counterbattens where they intersect the main joists, and then screw straight down.

 

[bobby_la_mesma]

Hi

Thanks for the tip. Can I ask though, the extra insulation measures 170mm high. If I only add a 75mm batten the insulation will have to be squashed to fit a loft board on top. Is this o.k.? Sorry to keep asking/

Just to go over what I want to do... I want to put 100mm insulation in the original 100mm high rafters and then add 170mm of insulation, then add a platform to store light stock.

Thanks

Rob

 

[Deluks]

You can't have it both ways. Use less insulation, get as much as you can in there, and you can compress slightly but don't overdo it. I'd say 2" thick battens and stick with 150mm insulation. You could use 100mm fluffy between the joists and 2" kingspan/celotex between the battens.

 

[samk]

I have the same dilemma. I also have 100mm insulation and want to cross batten to increase insulation to recommended 270mm and then board for light storage. How did you go about it?
Sam

 

[kevnurse]

IMHO the heating costs you will save by increasing insulation from 100mm to 270mm in a 2 storey house will not cover the price of the insulation material any time soon.

 

[Deluks]

I have the same dilemma.

Then you get the same answer