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How to install the roofing underlayment properly? 7 tips from China’s best roofing underlayments manufacturer SINOMTC

roofing underlayment requirements

SINOMTC roofing underlayments installation instructions

SINOMTC roofing underlayment is a next-generation product that provides superior performance for your roofing. You get all the proven protection of an asphaltic-based underlayment matched with synthetic elements to add safety and durability.

The hybrid technology combines asphaltic polymer & synthetic fabrics for proven performance. It deserved your trust.

5 TIMES STRONGER Than a conventional 30 Lb.

PROTECT YOUR CREW! When properly installed, will not shrink, wrinkle, or bubble!

EASIER TO INSTALL Easier & faster to install than other products, Twice the coverage than 30 Lb. felt.


Special and basic requirements:

1. Firstly roof and decks should be dry before the roofing underlayment installation application.
2. Unroll the SINOMTC roofing underlayment and use it just like the regular asphalt felt underlayment.
3. SINOMTC roofing underlayment may be applied at any temperature that is safe for the applicator to work.
4. SINOMTC roofing underlayment should be installed with Logo facing up, our hybrid roofing underlayment Can be left exposed if properly installed for up to 180 days.
5. SINOMTC roofing underlayment fastening requirements:
a. Use 1″ minimum diameter plastic cap or 1″ minimum diameter no more than 18″ centers on edges and 24″ centers in the field of the roofing underlayments.
6. These are the minimum acceptable application instructions for SINOMTC roofing underlayment. More stringent requirements of the building codes should be followed. For further details, see the ARMA Residential Asphalt Roofing Manual.
7. If the SINOMTC roofing underlayment is exposed for less than 48 Hours standard all staples are acceptable. But do not staple on the field.

peel and stick roofing underlayment

• Standard Slope (4/12 and greater)

After the deck has been properly prepared, cover it with one layer of SINOMTC roofing underlayment. Lay the SINOMTC roofing underlayment parallel to the eaves, lapping each course at least 2″ over the underlying course. If two or more pieces are required to continue a course, lap the ends at least 4″. End laps in the succeeding course should be located at least 6′ (foot) from the end laps in the proceeding course. Lap the SINOMTC roofing underlayment 6″ from both sides overall hips, valleys, and ridges. Where the roof meets a vertical surface, carry the SINOMTC roofing underlayment 3” to 4″ up the surface.

 Low Slope (2/12 up to 4/12)

Cover the deck with two plies of SINOMTC roofing underlayment overlapping 19-1/2”. Begin by fastening a 19-1/2″ wide strip of SINOMTC roofing underlayment placed along the eaves. Place a full 37.25″ wide sheet horizontally along the eaves completely overlapping the starter layer. All succeeding courses will be minimum 37.25″ wide and should be positioned to overlap the proceeding course by 19-1/2″.

hybrid underlayment

 Ice Dams

For all slopes, when there is a possibility of ice buildup along the eaves or a backup of water from pine needles or leaves, follow the above low slope guidelines to a point at least 24″ beyond the interior wall line of the building. Thoroughly cement between the layers using asphalt roofing cement conforming to ASTM D 4586. The cemented double-ply underlayment serves as the eave flashing. After completing the eave flashing, secure each successive course as described above in the fastening requirements section until the final roof covering is applied.

synthetic roof underlayment

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