Breathable membrane to keep loft space clean

Martyn_H

Hi

My loft has no felt under the roof tiles consequently everything gets really mucky. I've seen Cromar 3 Vent Light on ebay.

http://cgi.ebay.co.uk/Vent-3-Light-Breathable-Membrane-50m-x-1m_W0QQitemZ120569773718QQcmdZViewItem?rvr_id=220669958437&rvr_id=220669958437&cguid=1402fa9212e0a47a2eb773e7fe60163c&clk_rvr_id=276913128044&afsrc=1

Has anyone used this or a similar material?

Also, can it be stapled vertically (to save waste) or should it done horizontally?

Thank you.

Buttwhy?

I had same problem but used ECo Permavent which can be used in warm and cold roof situations but also comes in 1.5m widths so cuts down on install time and wastage from overlaps. I bought it off ebay too for a similar price.
It can be stapled in place and doesnt tear like similar priced products.
You should fit it horizonatly so if any drips get thru the tiles it can run down the new barrier. If you fit it vertically you'll need more and larger overlaps so costing you more.
Good luck

har0ld

You can just use poly sheeting stapled up as long as there is ventilation at the ends and you don't create any closed pockets that would trap moisture.

Martyn_H

har0ld wrote: »

You can just use poly sheeting stapled up as long as there is ventilation at the ends and you don't create any closed pockets that would trap moisture.

I'd rather not take any chances with poly but would still like an alternative to paying £38 per roll.

Martyn_H

andrew-b wrote: »

What is so important in your loft that you need to felt the entire roof? Or any of it for that matter? Most peoples lofts store junk that will never be used plus a few boxes of christmas decorations. If you really need to store anything up there simply buy appropriate storage boxes with lids or simply throw a dust sheet over the top.

A very good point and one that I've given some thought to. We've already got boxes and sheets but the dirt is quite unpleasant if it gets breathed in.

_gav_

Well our house had the same problem, built back in the 30s, no felt. Anyhow, I used Garden membrane/underlay, basically the weed supressent liner! :-) http://www.ebay.co.uk/itm/QUALITY-STRONG-GARDEN-WEED-STOP-MEMBRANE-UNDERLAY-MAT-/140621725070?var=#vi-content

It was easy to fix using a staplegun. It was breathable and best of all, relatively cheap :-) And it worked a treat, 24months later still all OK and best of all, no dust :-)

IHTH

martinthebandit

I think the problem with fitting any breathable membrane in the loft is that all the dust that would have fallen into the loft falls onto it and, eventually it becomes an unbreathable membrane.

I suspect that its storing up problems for a few years down the road.

Martyn_H

What is the recommended overlap for the breathable membranes?

sophieschoice

We have the same problem with dust in our loft and OH is thinking of plasterboarding it. Any reason not to use this method instead of the membrane/fabric? Also is the membrane fire retardant?

Martyn_H

The Cromar product appears to have fire resistance according to the downloadable datasheet.

Using plasterboard will be dearer, dusty to cut, harder to remove if you need to get to a broken tile from the inside, and slower to install. Most importantly, the roof timbers won't be able to breathe, so will be susceptible to rotting.

If my maths is correct, I reckon I can get away with either two 50m x 1m rolls, or one 50m x 1.5m roll (two rolls obviously dearer but easier to handle.)

Buttwhy?

Martyn_H wrote: »

What is the recommended overlap for the breathable membranes?

In a hoprizontal fitting position the overlap would be 100mm. The sheets usually have a dotted line at the overlap point which makes it very easy to get right.