Felt tar and slag roofing 3 ply 4 5 lb m ft 2 22 kg m 2 felt tar and slag roofing 4 ply 4 8 lb m ft 2 23 4 kg m 2.
Weight of 3 layer felt roof system.
Typically it s applied as a 3 layer system usually consisting of a perforated underlay a 2mm underlay layer then thick 4 5mm felt.
They are no longer laid with hot bitumen and have stone chippings put on top.
This type of felt roof comes on rolls and is laid with the aid of a very large blow torch that heats and melts the rear of the felt melting it onto the roof structure below.
None asphalt roll roofing 1 1 lb m ft 2.
They had a stereotypical belief they were only good enough for your shed or garage.
If the slope is greater than 4 12 which provides more water drainage from the roof use one layer of 15 felt.
Don t forget to add all roof assembly materials when calculating total roof weight.
Each of the three layers is laid in a half lap system so any joint in the roof is as far away as possible from another joint.
Three layer felt system.
Atlantic single ply system 17000 system 17000 plus system 5000 classic commodity systems.
It s available in rolls that are 8m long and 1m wide with a thickness of 4 2mm mineral or 3 8mm sand.
The weight of roofing constructions above the truss rafter may be estimated with the calculator below.
Fitted using a blowtorch the 3 layer felt roof system benefits from being more stable than the older methods.
Of course how many rolls you need will depend on the size of the roof so ensure you measure correctly.
The 3 layer felt roof system is also versatile when it comes to appearance.
If the slope is between 3 12 and 4 12 use two layers of 15 felt for asphalt shingles.
Three layer felt systems have come a long way from the early days.
Anderson tecnatorch sbs torch on mineral felt capsheet is used as the final layer of the felt roofing process.
The products used today are a 3 layer membrane system applied with the use of a gas gun.
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The type and amount of roofing felt to apply varies according to roof slope.
When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.
Second layer is a sanded underlay which is to.
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Use our table below to compare membrane thickness and weight for our range of flat roofing.