屋顶shingles下面有没有规定要铺tar paper？

[闲丸]

还是屋顶，builder说他们屋顶上不铺tar paper就钉shingles。这是符合规范的么？tar paper对防止漏水来说是必须的么？

 

[stevenw]

以前看过要求，好像是边沿1-2ft必须先垫铺一种材料，然后再上shingles.

 

[闲丸]

恩，builder说他们边缘铺一种membrane来防止ice dam，但是其他地方就不铺tar paper了，直接上shingle。
你说这是符合规范的？

以前看过要求，好像是边沿1-2ft必须先垫铺一种材料，然后再上shingles.

 

[Ayin_Ottawa]

恩，builder说他们边缘铺一种membrane来防止ice dam，但是其他地方就不铺tar paper了，直接上shingle。
你说这是符合规范的？

Yes, OK.

2. Ice Shield (also known as ice and water shield, or I&W) is a thick asphalt or bitumen based reinforced membrane. This membrane has a sticky surface, that glues to the roof deck, and does not tear after installation. In Northern states and Canada, building codes require the usage of ice shields, because it protects the roofing structure from water penetration caused by wind-driven rain and ice dams. It is essential to use an ice shield in critical areas such as eaves, rakes, ridges, valleys, dormers and skylights. It is best to install the ice shield when air, roof deck and membrane temperatures are at or above 40°F (4.4°C). For best protection, an ice shield should be installed at the bottom 3 ft of the roof. The rest of the roof can be covered by regular underlayment (felt or synthetic)

The down side of an ice shield is that when it is installed over the entire roof deck, it also acts as a vapor barrier, which means that it traps water under the roof. Trapped water can cause the substrate to rot and will also lead to the formation of allergenic mold and mildew. As a result, it is generally recommended to avoid covering the entire roof with an ice shield.

http://www.roofingcalculator.org/tag/tar-paper

 

[闲丸]

感谢
你给的这个链接上说除了在eaves，valley要铺ice shield之外，真个roof还要铺一层felt(tar paper)。我问的其实是这层 tar paper，到底是不是building code所要求的。

Yes, OK.

2. Ice Shield (also known as ice and water shield, or I&W) is a thick asphalt or bitumen based reinforced membrane. This membrane has a sticky surface, that glues to the roof deck, and does not tear after installation. In Northern states and Canada, building codes require the usage of ice shields, because it protects the roofing structure from water penetration caused by wind-driven rain and ice dams. It is essential to use an ice shield in critical areas such as eaves, rakes, ridges, valleys, dormers and skylights. It is best to install the ice shield when air, roof deck and membrane temperatures are at or above 40°F (4.4°C). For best protection, an ice shield should be installed at the bottom 3 ft of the roof. The rest of the roof can be covered by regular underlayment (felt or synthetic)

The down side of an ice shield is that when it is installed over the entire roof deck, it also acts as a vapor barrier, which means that it traps water under the roof. Trapped water can cause the substrate to rot and will also lead to the formation of allergenic mold and mildew. As a result, it is generally recommended to avoid covering the entire roof with an ice shield.

http://www.roofingcalculator.org/tag/tar-paper

 

[闲丸]

抱歉麻烦各位了。自己读了building code，这里通报一下。eaves projection (ice shield)和shingle下面的tar paper，都是building code里要求的。

9.26.6. Underlay Beneath Shingles

9.26.6.1. Materials
(1) Except as required in Sentence (2), when underlay is used beneath shingles, it shall be,
(a) asphalt-saturated sheathing paper weighing not less than 0.195 kg/m², or
(b) No. 15 plain or perforated asphalt-saturated felt.
(2) Underlay used beneath wood shingles shall be breather type.
9.26.6.2. Installation
(1) When used with shingles, underlay shall be installed parallel to the eaves with head and end lap of not less than 50 mm.
(2) The top edge of each strip referred to in Sentence (1) shall be fastened with sufficient roofing nails to hold it in place until the shingles are applied.
(3) The underlay referred to in Sentence (1) shall overlap the eave protection by not less than 100 mm.

 

[Timothy's]

Most builder don't use it. But If I replace my roof I would ask roof to install it if the shingle manufactor required them.
"
THE USE OF UNDERLAYMENT WITH ASPHALT SHINGLES
There are many reasons why the use of asphalt-saturated felt as an underlayment prior
to applying asphalt shingles makes good roofing sense.
l Underlayment protects the wooden deck from moisture penetration until the
shingles are applied, thus greatly reducing problems that can arise when shingles
are installed on a wet surface.
l Many asphalt roofing manufacturers specify the use of asphalt-saturated felt over a
wood roof deck to validate their warranties.
l Asphalt-saturated felt should be used beneath asphalt shingles reinforced with
glass fibre felt, since this is a requirement for Class A fire resistance.
l Installing asphalt-saturated felt helps to minimize "picture framing", i.e. the visible
outline of deck panels caused by irregularities in roof decking thicknesses.
l The water resistance of asphalt-saturated felt provides secondary protection by
helping shield the deck from wind-driven rain.
l Asphalt-saturated felt also offers protection to the shingles from the resins that can
be released by the wood board decking.
l The underlayment material should meet at least one of the following industry
standards:
a. CSA 123.3-M - No. 15 / ASTM D226 Type 1 (No. 15 felt)
b. CAN 2-51.32 - Breather Type Sheathing Paper
The proper application techniques recommended by the manufacturers should be
followed to ensure optimum performance of asphalt-saturated felt.
[return to listing]
Canadian Asphalt Shingle Manufacturers' Association"