Breathable Roof Membrane - Recommendations

[Steveb21]

Hi,

Any suggestions on which membrane to go for? Will be my forever home and replacing approx 260m2 of roofing so don't want to end up going for some poor quality material.

Klober Permo Forte Breathable Membrane 1.5m x 50m (75m2 roll) - This any good @ 150gsm?
Coming in at approx. £150 per roll though!

Also, might be a silly question however does the color of the material have any noticeable factor in heat retention etc?

 

[datarebal]

Shop around for the permo forte. It's a good product

 

[Steveb21]

From searching this site it appears what most recommend. £135 a roll is the cheapest i can find.... some places are selling at nearly £200 a roll!

Permavent Max Membrane - Any one had any experience with this? 150gsm for £65 a 1x50m roll.

 

[^woody^]

Look for an "air permeable" or "air open" product also referenced by AP or AO or suchlike. These are higher performance membranes, and be aware that even some premium membranes are not air permeable.

 

[Steveb21]

Look for an "air permeable" or "air open" product also referenced by AP or AO or suchlike. These are higher performance membranes, and be aware that even some premium membranes are not air permeable.

Does the Klober Permo Forte fall into this category?

 

[^woody^]

No, I think Permo Air is the more breathable

 

[Steveb21]

No, I think Permo Air is the more breathable

Nearly £200 a roll then!

If using a breathable air membrane do you still need to leave 50mm gap between membrane and insulation (in between the rafters).

I have 225m joists, was planning on using 165mm celotex leaving a 60mm air gap. If the air gap is not required or can be reduced, i might increase insulation to 200mm leaving the 25mm air gap. What are your thoughts?

 

[^woody^]

Nearly £200 a roll then!

If using a breathable air membrane do you still need to leave 50mm gap between membrane and insulation (in between the rafters).

There are other manufacturers with similar products.

Whether a gap is required depends on the manufacturer's guidance. You will tend to find that air permeable products require less or no air voids to work.

 

[bhm1712]

How about this one?

Protect Viking Air - Type LR Air and Vapour Permeable Underlay

A fantastic premium type LR roofing underlay for a range of different buildings and structures, this outstanding product offers near-unrivalled air and vapour permeability. It can be used in both warm and cold pitch roofing projects and tested rigorously by third parties in order to ensure that...

www.roofingmegastore.co.uk

 

[Steveb21]

How about this one?

Protect Viking Air - Type LR Air and Vapour Permeable Underlay

A fantastic premium type LR roofing underlay for a range of different buildings and structures, this outstanding product offers near-unrivalled air and vapour permeability. It can be used in both warm and cold pitch roofing projects and tested rigorously by third parties in order to ensure that...

www.roofingmegastore.co.uk

£300 a 1.5m x 50m roll. Never knew they cost so much!

I have contacted Viking and Klober to clarify what the airgap should be from insulation to membrane. If a 50mm gap is still required i may just go for the Klober Permo Forte.

 

[datarebal]

Ask someone who actually use and know the product.
Kpf all the way