Felt or tyvek?

I noticed a new house roof had been underlaid with Tyvek. Dunno if roof will be shingles or metal. Anybody got preferences? Reasons? If it makes any difference, the non-roof sheathing is OSB.

am sure tyveck is breathable

tyvek is not for roofs at all. it may have been titanium UDL synthetic underlayment.

we use tyvek here in scotland for roofs

I would not use it on a roof.

its good because its 50m rolls and its 2m wide we use it for under tiles or under slate

I hope yopu dont slip on that stuff. Ive never seen it and i probally never will.
Keep your harnees on at all times eh.

am never sober to remeber a harness lol just kiddin

Sounds expensive and unecessary to use Tyvek that I know unless they have other products.

well if your paying top dollar for a new slate roof am sure youd want the best underlayment as well

you use tyveck because it vents the roof through the slate just makes sense to use it

Yes, if the customer is paying top dollar for one of the best roofs the whole entire system should be that way. If Tyvek is necessary for slate then it should be used. Does Tyvek increase the lifespan of slate roofing?

no underlay is required with slate its just to keep it cool in the summer warm in the winter and to keep it dry while u get it layed but using tyvek stops the need for vents etc

I dont even give the home owner the option of using tyvek. Nobody in my area uses it and if they did id laugh at em.
Tyvek is designed for the exterior wall underlayment for siding PERIOD.
If your using tyvek for shingle underlayment then your wasting alot of money.
Felt does the jod all to well to change that.

DuPont currently possess two main Agrément certificates which approve the use of Tyvek® membranes in both warm and cold pitched roof construction. These are categorised according to the positioning of the insulation.
In cold roofs, the insulation is installed at joist level with a cold loft - space (attic) between the insulation and roofing underlay.
In warm roofs, the insulation is installed at rafter level.

Sealed roofs are roofs with no airflow beneath the underlay and with all air leakage paths sealed. They will be more energy-efficient than non-ventilated roofs and will provide a higher degree of comfort. Tyvek® non-ventilated roofs will significantly:

Reduce the likelihood of condensation
Have less air leakage
Minimise the heat losses caused by air infiltration

its just based on a roofers personal opinion whatever they use

Looks like Slater set Buster right on that one with the approval regs (for the EU, anyhow).

I am in the process of a 12x12 shed & 12x12 chicken coop for my Mom’s place; going down with snap lock .24 mill finish metal panels. Both are 6:12.

I used Atlas Summit instead of 15 #… I wanted something breathable but longer lasting than the regular old felt thing.

thats the thing with it to ranchhand it dosent rot like normal felt has a very long life

i sometimes use this to this is good gear klober.co.uk/product3.php?id=86

u can get unbreathable too klober.co.uk/product3.php?id=112