Now that Fall is here, I thought it might be the right time to start talking about roofing and siding on manufactured homes. If you check the Manufactured Home Construction & Safety Standards (3280.307) you won’t find a lot of detail. Basically, we need to use corrosive resistant fasteners (shipped from the factory for new homes) to attach an exterior covering that must prevent infiltration of air, water and vermin.
Bottom line, the code requires that we install the exterior coverings to the product installation instructions. So, it is smart to read the shingle bundle wrapper, the siding box, or the little instructional insert found in other products.
Let’s take a closer look at some of these roofing and siding products, starting at the top. Roofing! I am going to try and focus on issues that installers are faced with, and what I most commonly see in the field in regards to roofing:
1. Shingles damaged by the factory installed wind deflectors.
I know you have seen furring strips nailed to the roof with so many nails or staples you can barely get a pry bar underneath to pull them free! Inevitably, the shingles get damaged trying to pull the strips off. And what do you do about the holes left behind from all of those nails? Here is the kicker, when a shingle is damaged, it should be replaced. There is no approved method in any of the installation manuals I have seen that show how to repair a shingle. If your manufacturer is shooting way too many nails in these strips, take some pictures and send them to the QC manager! And ask for a design for proper repair!
2. High fasteners that prevent shingles from sealing together and allow wind under the tabs.
If the nail head or staple crown prevents proper sealing because it is not driven flush, the shingle can blow off or the fastener can even cut through the tab.
3. Over-driven fasteners are just as bad! A nail head or staple crown that cuts into the shingle will surely lead to shingle flying off on windy days.
4. Hinged roof shingles not lying flat. You can’t assume that the shingles will lay down over time. The manufacturers rely on you for feedback on how the hinged part of the roof knits together. So, make sure you report any problems back to them!
5. Drip edge projecting past the shingles. This is a problem when the installer has to install the last few feet of drip edge to reach the peak of the roof or along a hinged area. If you can’t slip the drip edge under the shingles so that there is at least ¼” of shingle past the drip edge, you need to report it to the manufacturer. Don’t cut the drip edge to go around a rogue nail or staple.
The other issue that I think we should look at is ice dam protection. To protect the eaves of the roof from water infiltration due to ice damming, manufactured homes produced for cold climates are provided with a type of ice and water shield. The Asphalt Roofing Manufacturers Association (ARMA) says that in areas where the average January temperature is 25° of less, ice dam protection is needed. I typically see manufacturers use either a self-adhesive product, or they use a multi-layer application of roofing paper that is roof cemented to the roof decking and covered with a second layer of the same paper cemented to the first.
In both cases, the ice dam protection extends from the edge of the roof deck to a point 24” past the interior wall finish of the exterior wall. Should you be called upon to repair any damaged roofing along the eaves of the home, make certain you are provided the needed designs to properly correct the ice and water shield.
Generally the top reason an ice dam forms along the eaves of any home is due to improper roof ventilation! The HUD code requires that there be a 1” air space under the roof decking to eliminate cold spots that would lead to freezing of any water running down the roof. Should you have a home with ice dam issues, report it to the manufacturer and ask them to check the roof insulation!
Ok…next time we will talk a little about vinyl siding!