Roof underlayment installation , roofing felt , or " old salt paper , " is an important step when roofing a building . Here ’s how to do it .
Before applying roofing , you ’ll demand to cover the sheathing with roofing mat , also often called " tar newspaper . " Most local codes call for using 30 - punt felt . Some roofers prefer to attachfelt underlaymentwith one - inch roofing nails , or special nail with plastic washers , but most codes take into account staples , which are easier to get . For the lower portion of the roof — specially the part that overhang the eaves and is susceptible to ice-skating rink dekameter — it ’s a good musical theme to apply ego - reefer waterproof shingle underlayment ( WSU ) , also called water ice guard .
Underlayment , flashings , and shingles all wreak together and must be install in the right order . If you lay the felt perfectly true , you’re able to use its lines ( or else of horizontal chalklines ) to align the shingles .
Do not utilize mat as a impermanent protection against rain : If it gets wet it will purse , making it harder to shingle . If you involve to temporarily protect a ceiling , cover it with plastic sheeting or a tarpaulin .
When turn with a helper , expect to spend several hours to add the drip bound , WSU , and roofing palpate on a medium - sized ceiling . Prep for the projection by sweeping the sheathing sporty of all debris and ensure there are no nails or sliver poking up .
What You’ll Need
Equipment / Tools
Materials
Instructions
Apply and Attach the Drip Edge
Apply the drip border to the eave . Cut the drip edge flashing at an slant at the corner , press it lightly against the eave death ( not too hard or you ’ll misshape it ) , and drive a nail near the end . expend a chalkline or ordinate it by eye to check that it ’s straight , then drive roofing nails every foot or so to fasten it to the sheathing .
Overlap and Cut the Drip Edges
Where the drip - border bit forgather , overlap them by at least 2 inches . Where the drip edge meets a valley or a hip , cut the firearm with overlapping tabs . Press the tabs firm to make snappy corner with no gaps and attach them with roofing nail .
Align the Felt
Snap a chalkline to aid you line up the WSU or experience . The WSU should beetle the drip mould sharpness by 1/2 in , so crack a line that is 35 - 1/2 inches above the dribble edge . tick at several point in time to make certain the overhang is consistent ; it does not have to be everlasting , but you may need to realine the dripping bound .
Roll Out the WSU
Using the chalkline as a guidebook , roll out about 12 feet of WSU that ’s smooth and loose of creases and bubble . Often you could re - wander it , then unroll it while peeling off the paper support . On a outrageous cap , you’re able to cohere the bottom one-half first , then take out off the backing from above . quash creases and stay adjust with the chalkline . Press down to tightly seal the WSU .
Apply the WSU at a Valley
No matter which vale method acting you use , for extra protective covering apply WSU at a vale . Snap chalklines on both sides for template . Roll out and smoothen the WSU and drive a few nail on one side to hold it temporarily . Fold over the other side and undress off the paper backing . Press it into seat , remove the nail , and strip off the paper on the other side .
Stay Parallel
convergence feel course at least four inches . Snap a chalkline 32 inches above the top edge of the WSU or utilize the lines on the felt as guides . If you use the pedigree as template for installing shingles , value up from the drip mould boundary to reassert that you stay parallel . Roll out the felt , wipe out creases or bubble , and drive at least three raw material every foot .
Apply the Felt
Apply felt right up to the ridgeline or to no more than 4 inch below it . ( Rather than cut the felt horizontally to fit , overlap it by more than 4 inches . ) Apply felt on the ridge so it overlaps at least 8 column inch on each side . decimate creases and bubbles .
Attach Where the Roof Meets Wall
Where the roof meets a bulwark , lap the felt up 4 inches if potential . crowbar aside the siding and slip the felt under the siding . In some situations , you may have to temporarilyremove the siding and replace itafter installing the underlayment , shingles , and flashing .
