roofing membrane differences?

[julianf]

Is there any real difference between all of these -

Vent3 Double Sided Breather Tape - CROMAR BUILDING PRODUCTS

Vent3 Double sided tape is a modified acrylic, high strength adhesive tape used to create an air-tight lap between successive layers of underlay/membrane.

www.cromarbuildingproducts.com

Vent3 Classic - CROMAR BUILDING PRODUCTS

Vent3 Classic is a breathable roof underlay for cold and warm roof applications which give major benefits over traditional roof underlays. 115gsm

www.cromarbuildingproducts.com

Vent3 Classic Xtra - CROMAR BUILDING PRODUCTS

Protect1F is a non breathable roof underslating which gives you major benefits over plastic and traditional 1F bitumen based underslating felt.

www.cromarbuildingproducts.com

Vent3 Light - CROMAR BUILDING PRODUCTS

Vent3 light is a lightweight breathable roof underlay for cold and warm roof applications which give major benefits over traditional roof underlays.

www.cromarbuildingproducts.com

Breathable Roofing Membrane Underlay Vent3 PRO

Breathable Roofing Membrane Vent3 PRO is a heavyweight, high performance underlay for cold and warm roof application. 165gsm.

www.cromarbuildingproducts.com

And, this one isnt called "vent" but seems the same again -

Roofshield permeable pitched roofing underlay

Roofshield is a low vapour resistant, air permeable and highly watertight breather membrane as a pitched roofing underlay.

www.cromarbuildingproducts.com

Thank you.

 

[gaz1]

just one thing cost for a roll

really its a big conn like dvds are for a film what should be one film is released 5 times with different cuts

it happens with any products out there

Maintenance

Cromar Vent 3 Classic 115gsm 1Mtr x 50Mtr

Vent3 Classic is a triple layer fabric, high performance breather membrane, made from high tensile spun bonded polypropylene layers, around a micro‐porous polypropylene film. Designed for use in a fully supported or unsupported tiled, slated or metal roof system. The high vapour permeability and...

buildingplasticsdirect.co.uk

we also buy 1.4-1.5m rolls as well

 

[JimmyS]

Main difference between them is the breathable and non-breathable part. Depends on the roof construction but for example if its a standard pitched roof with insulation between the joists then you need to ventilate the roof space to stop interstitial condensation happening. You can use roof vents/ ridge and eaves vents or you can use a vapour permeable underlay. If you dont vent it properly and its insulated then you can end up with problems.

Jimmy

 

[julianf]

Main difference between them is the breathable and non-breathable part. Depends on the roof construction but for example if its a standard pitched roof with insulation between the joists then you need to ventilate the roof space to stop interstitial condensation happening. You can use roof vents/ ridge and eaves vents or you can use a vapour permeable underlay. If you dont vent it properly and its insulated then you can end up with problems.

Jimmy

Thank you.

If you look at the links they all say breathable - so that's not the difference.

 

[JimmyS]

Thank you.

If you look at the links they all say breathable - so that's not the difference.

3rd one down is non breathable. Other difference is the weight and presumably strength. Traditionally up here we use sarking under the tiles/ slates. Down your way I don't think its that common. If you happen to fall between the tile battens for example (if roof is being tiled) then all that's between you and the floor may be the roof membrane. The thinner stuff may not be as strong, only other difference I can see.
Its becoming more common on new builds up here by house bashers to just not use sarking to save a few bob not sure if some of the roofers are as keen, especially if the membrane is really thin.

Jimmy

 

[gaz1]

3rd one down is non breathable. Other difference is the weight and presumably strength. Traditionally up here we use sarking under the tiles/ slates. Down your way I don't think its that common. If you happen to fall between the tile battens for example (if roof is being tiled) then all that's between you and the floor may be the roof membrane. The thinner stuff may not be as strong, only other difference I can see.
Its becoming more common on new builds up here by house bashers to just not use sarking to save a few bob not sure if some of the roofers are as keen, especially if the membrane is really thin.

Jimmy

ive been north and south and im in the middle working

theres no difference whats so ever other than price and thickness between them

Ive done the job most of my life grew up with the old tar felt thats now over heated and sagged or torn apart the old house dosnt even have any of that stuff in and it lasts way longer than these new builds that i can assure you of and that uses lime between stone slates

anyway battens down here for lower costs, i am aware of the boarding that scotland has but we also have it on old buildings down here not by much though

only differene with proper boards under the slates is it holds better also costs more in the long run i can see the point in less usage by using lathes instead of boards

 

[JimmyS]

Battens are becoming more common here as well. Other issue with the sarking is that if the roof gets damp then the gaps that are supposed to be left between the sarking boards can close up so its not vented if its a breather membrane set up. Im having to get the roof here re-slated as previous folk stripped slates and put on stonewold tiles many moons ago - a lot of which are knackered. Ended up going with SSQ Domiz slates, they are spanish but seem ok.

 

[gaz1]

the old stuff is based on this method

new stuff

all based on the wool industry machines