While performing a one-year guarantee review at a brand new house, a home inspector found standing water on a sloped roof. It was clear the roof pitch over this newer veranda add-on was too shallow for the composition shingles that were installed above it. And there was actually no reason for this kind of blunder.
Capitol Roofing, Inc. and Management owns the special one-year old house said the home had paid a private contractor to construct the add-on several months earlier. Sadly, the home – like most home owners – failed to understand about the need for matching the roof covering material to the angle of the roof pitch. Not following a manufacturer’s setup directions can result in serious roof leaks, even mould. The home inspector reported the identified flaw to the home owner, and counseled her to request the contractor to return and fix it. The home consented to your telephone consultation with the contractor, if it became mandatory.
The Roofer Is Assumed to Match the Substance to the Roof PitchIn building-talk, “roof pitch” is a term used to describe the angle, or gradient, of the roof surface. Pitch is normally expressed by a phrase like “5 in 12,” or “5:12,” or occasionally simply “5 pitch.” In this case, the phrase means that for every 12″ of flat measurement from the roof edge, the roof surface gets 5″ higher. It is simple to find out that the water dropping skill of a roof will have a great deal to do with how high the pitch angle is. Saying it another way: “the higher the pitch, the quicker the water will run off a roof.”
Because of this, they’ve a keen interest in those shingles being installed right. So these makers print the setup directions ON EVERY PACKAGE OF SHINGLES. And, in those directions the manufacturers urge that the roof pitch be greater than 4 in 12, so that water will run off correctly and economically. If a roofer uses makeup on a roof with a pitch of less than 4, specific preparations must be performed, like doubling up the roofing felt, and using sheet metal flashing at valleys, etc.
Now, here’s where it gets interesting in our special narrative. In fact, breaking that instruction and a few others will void the warranty on the whole roof. In other words, composition shingles aren’t designed or meant to be used with a shallow roof pitch. Wind-driven rain will really blow water back up under the shingles, under the felt and the wood deck will get wet, and neglect to dry correctly. Over time, this wet deck will warp and rot, and flow.
If a home inspector or a roofer sees water standing on a pitched roof, it’s a fairly good hint that there’s not enough pitch angle to the roof deck. This is a clear indication that the roofer shouldn’t have used composition shingles on that surface. The contractor who constructed this woman’s veranda add-on, didn’t understand, or simply did not care. This home owner should whine, and the roof covering should be changed out at no cost.
What exactly is the Appropriate Way to Roof a Low-Sloped Roof?
But, what materials should you use to cover a low-sloped roof?
Roofing materials manufacturing companies make a product with similar surface granules and matching colours, called rolled roofing, which comes in 36″ wide rolls. This “rolled roofing” is to be used by, first doubling up on the layers of roofing paper, overlapping each run as it progresses away from the lowest roof edge. Subsequently, starting again at the lowest roof edge, the composition rolled roofing is rolled parallel with the roof edge, and the overlapping parts/seams no less than 1″ wide are hot mopped with pitch or roofing cement.
An Inspector Can Supply a Little Peace of Mind if you’re Going to RemodelIf you’re contemplating a roof replacement for any motive, call a professional real estate inspector. And, that goes for any and all remodeling jobs around your house. In most states, inspectors are called by the common term “Home Inspector.” If your state requires a permit to perform these services, by all means use a accredited inspector. Some firms will willingly act as a consultant between you and your contractor. It is advisable to contact an inspector early, before things get testy between you and your contractor.
There are different kinds of substances which are available for these low-sloped applications, but generally speaking, the all roll out and are sealed at the seams to keep standing water or wind-driven rain from getting up under the roof covering. After all, the function of your roof covering materials, and the flashings that supplement them, is to keep the rain and wetness out.
If you’ve already had an inclusion done or a roof replacement, and you would like a second opinion, call a home inspector. Most review firms perform “system” reviews, where they just consider the individual systems and parts that were remodeled or upgraded. Do a little research and test with your buddies, or with inspector trade associations, like the American Society of Home Inspectors ASHI, or the like, to find firms who hold the greatest standards or professionalism.
What is the Take Away?
If you, or someone you understand, are about to intend a remodel or update, it is wise to get someone on your side who understands how the work is assumed to be performed… someone who can guide you and/or your contractor about the correct strategy to do it.