This is the fourth part of a multi-part outline of what is involved in buildings a Habitat house. This article covers the steps in installing roofing – felt and shingles and a few other roof line details such as building a “bird box”, installing the drip edge and vents. The first part is Habitat Tutorial – Prepration for Build which covers some of the pre-build steps the Site Project Manger (SPM) and selected volunteers go though just to get ready for the volunteers, the second is Habitat Tutorial – Part 2 which covers the first day where the walls go up and the third is Habitat Tutoial – Part 3 which covers raising the roof structure. In addition, there are four sets of pictures with slide shows that have already been published that you may be interested in as they concentrate on people on the job site – volunteers. The first is Habitat for Humanity – 2008 Dinner on the Slab consisting of 25 pictures including our future homeowner Nicole Combs and her son Elijah. The second includes 115 pictures of the first day of the build – Habitat Build 2008 – First Day – Walls Go UP . The third is: Habitat Build 2008 Second Day – Roof Goes On which has pictures and blog on the installation of the roof trusses and decking the roof. The fourth is Habitat Build 2008 – roofing and siding. If you want access to any of the tutorial pictures they are all in one place for all the tutorials to date. Tutorial Slide Show – 146 pictures so far, including many not in this article.
Note: If you came here looking for the homeless veterans site, this is it! If you came here looking for the homeless youth site, this is it!. I’m just taking a break to help out on a Habitat House and once a year I post what I saw, experienced and learned. Click on either of the two links in this paragraph or go to the side bar and select a category or search for what you want. Also look above the banner or to the right for popular articles on Homeless Veterans.
Tutorial – installing roofing shingles
This is the way Habitat volunteers see the house when they arrive on the scene on roofing day. Soon the roof will be covered front and back with volunteers. It is essential that the roofing be done early in the day and that there is plenty of water available. The felt and starter shingles are already in place.
We need to start this tutorial a little earlier than that.
This drawing illustrates drip edge installation. The drip edge must be installed in the order shown. The drip edge is a metal extrusion that goes along the horizontal edge (eave) of the roof under the roofing felt and along the sloping edge (rake) of the roof above the felt. Install the drip edge for the eave before the roofing felt is installed. Install the drip edge for the rake after the roofing felt is installed. Attach the edge using 7/8 ” roofing nails on 24″ centers. Unlike shown in the drawing, the rake edge goes all the way down and overlaps the eave edge. Trim the rake edge to match the eave using tin snips. When two pieces of drip edge meet in a joint, overlap the joint by 1 to 2 inches by trimming the top of one as needed to allow them to overlap. Joints on the rake drip edge should should have the upper one overlapping the lower one.
Also shown in this illustration is something called the “bird box”.
Click here for the rest of this tutorial:
This is the “bird box” detail for the corners of the roof. It is simply a 2 piece box that adds detail to the house and provides a place to mount corner lights. It just adds to the overall looks. Notice the rake drip edge is shown trimmed in this illustration and runs all the way to the facia.
Roofing Felt Installation
The edge of the roof is outlined with starter shingles that are placed on the roof with the tabs turned inward. This provides extra strength near the edge, higher wind resistance, and better resistance to water blowing under the edge of the shingles. Before starting, snap a line 11″ from the drip edge on the eave all the way across the roof. Have someone hold the line down in the middle of the roof and snap each side separately to minimize bounce and sag. Repeat for the rake (sloping) edge.
The starter shingles are nailed along this line, allowing a uniform 1 inch overhang of the shingle over the drip edge on both the eave and rake (12″ shingle on 11″ line). Notice that the eave edge starts with a shingle that has 1/2 tab cut off (6 inches) in the drawing, although that is optional in many areas. Outline the roof completely with these shingles. Butt the starter shingles end to end (do not overlap). Each shingle gets 4 nails located near and opposite the beginning of the drip line. See drawing “shingle layout below” if there is any doubt.
Trimming the Edges
The shingles should overhang the end (rake) of the roof and droop down until the entire roof is covered.
Shown above is the proper installaion around a typical vent pipe. The flashing will already be there but not nailed down. Lift the flashing up and run the course below up to the pipe and notch as necessary. In the case shown above the pipe flashing has been dropped over the lower course and the follwing courses lap over the upper parts of the flange so that water sheds properly. The boot is sealed to the roof with asphalt calking and nails below shingles. Any nails are calked and located under shingles.
Shingles for Valleys
There are two ways to install shingles in valleys. Both start with a 14″ wide aluminum sheet pressed into the valley from top to bottom. Roll out the aluminum and form it to the shape of the valley down the center of the sheet. Nail this sheet only on the long side edges. No nails within 6″ of the center!
The drawing above shows the valley weave technique that is usually used on valleys between two roofs on the front of a house, sometimes also on the back. Shingles woven together both look better and hold up better to water dammed up from leaves on the roof.
Shingles from the shorter roof are extended to and lap over the valley but the ends on the other side are not nailed down at that time. Shingles from the other roof are woven in by crossing over one shingle and slipped under a shingle in the next course and nailed down. Form both sets of shingles snugly to the bottom of the valley. It is best to trim the ends as necessary to not extend under more than one course at a time to avoid a lumpy appearance. Do not put any nails within 6 inches of the valley from any direction!
Install the aluminum as described above. Run the shingles from the shorter roof side over the valley and lap the other side by at least 12″. Make certain that no end joints end up in or near the center of the valley, preferably end them near or past the edge of the aluminum. Form the shingles snugly to the bottom of the valley. Do not place nails within 6″ of the center of the valley at any time from any direction!
Snap a chalk line down the center of the valley. Now extend the other side of the roof past the chalk line and cut it to match the chalk line. Cut only the newer layer, not those from the short side. The effect is one side is slightly higher than the other, forming a small step. Apply a bead of asphalt caulk about 1″ back from the cut edges and press it in.
Slide Show of Tutorial Pictures.
This Roofing Tutorial slide show contains all the pictures shown here and quite a few more.
Here is a link to the Roofing Tutorial pictures
Here is a link to my Habitat Build Photo Sets
There is at least one more tutorial coming, Hardi Plank siding.
Do you find these tutorials and pictures useful? Please let me know!