Photographs of issues with the material covering your roof found during home inspections.
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Type Of Roof Covering
These tiles are made of cement. They have the same issues that clay tiles have when you consider installing them. In this case, there may be an additional concern. These tiles were made in 1931, which may mean that they have asbestos fibers in them. Using these fibers helped create a sturdy tile. The fibers can be released if the tiles are cracking.
Sunny days cause shadows. This photo shows the ridge detail for these same cement tiles. Tile roofs seem to experience problems on the ridges first in my experience. Some are cracked here. There were tiles missing from other ridges. Note: it is not safe to walk on tile roofs, so if you have a problem with one, it is best to leave the repair to a professional roofer.
This roof had been protected with paint, which has worn off. This has led to the beginning of rust. Metal roofs can be shaped to look like ceramic tiles, flat sheets, or other shapes. The roof here is from a home built in the 1960s. Newer metal roofs have better coatings which may last longer.
Flat roof systems will often have a membrane installed. More commonly used for residential structures is the composite sheet. Whereas as membrane will be a solid sheet covering a larger area, composite sheets come in rolls that are easier to handle. The material is the same as a composite shingle. The term composite comes from the fact that there are several layers that make up the covering. The top most layer has some type of UV protection, which would be the small pebbles. When these are in place, the materials do not deteriorate as quickly from the sun light.
This type of roof covering can be long lasting. You do not want to walk on this surface though. The tiles are held in place by a fastener through a hole in the tile. This is a weak point that can break when someone is walking on it. I often find loose tiles when examining these roof surfaces. Cracked tiles can also e a problem.
Type of flashing around roof penetrations:
The plastic flashing above is not all plastic. Some of these vents are. The plastic is not only used for plumbing vents. They could be dryer vents or vents for attic ventilation. The vents referred to as plastic vents have the problem that they can break down faster on a roof surface than the metal. However, as pictured here, both metal and plastic can have problems over time. The metal vent had to be sealed on the top with caulk to prevent leaks. The plastic vent here has a metal base that is rusting. Generally, I like to inform my clients of the material, because this can effect maintenance over time.
Type of flashing along wall to roof joints:
Many homes have designs where a wall for a second story space meets the roof covering an area without a second story. Here we see the roof sloping down towards the front yard. The flashing that goes under the wall covering and under the shingles helps prevent water from entering the internal wall structure.
An acceptable building practice is to have this flashing be on single piece. This is done on many masonry/ brick homes because the appearance is better. However, in Houston’s climate, this flashing style is not the best. Water stays behind the flashing all the way down the roof, giving the water the chance to seep into the home.
Instead of having one single piece, step flashing direct the water from beneath the shingle to the shingle surface. As seen here, the wall covering can come quite close to the roof covering, which is not always good. To check on flashing type, we look for signs that it may be stepped or not. In this case, the flashing coming out from underneath the shingle is an indicator that the flashing is stepped.
Condition of and previous repairs to flashing, skylights, and other roof penetrations:
This vent is starting to rust. Rust allows holes, which permits water to enter the attic. You would be surprised how much water can enter. What is also interesting here is that staples were used to fasten the flashing of the vent. Staples were also used for the shingles. This is not common, but staples should be treated like nails. You want to see them caulked. Rusting staples or nails can cause leaks too.
Skylights can be sources of leaks. This one has a good deal of caulking along the top flashing. Since the side is flat, it can hold water. A better design would be an upside down V to shed water from this area. The cable in the picture is for the television. Being loose, the cable can whip around in the wind, causing damage to the roof covering. These cables are often not secured to the home.
Plastic plumbing vents have to be examined more often than the lead vent flashing. The problem can be that they were not well installed, or the movement in the house causes problems around the seals. This can lead to leaks. On this vent we see that caulk had been added, but you can see that the movement has caused this seal to break.
This may belong in the Wall section, but this is something you may not notice unless you are on the roof. A new wall covering was being installed onto the home. Here the installer has to be concerned about having proper flashing from wall to roof, and then install the siding panels to fit well in the space. Roof lines like this one make it hard to fit, so mistakes can be made. In this case, the installer has not completed the job.
The joint where a roof meets a wall should have the step or single piece of flashing, but there can be another issue: wall cladding coming into contact with the roof. I usually refer to this as the roof to wall joint on my reports. There should be a gap between the cladding and the roof surface to prevent moisture damage. Water running down the shingles can penetrate the wall covering. Having an inch or two inches of separation would be best. In the photograph, we have a porch roof added to the garage, so this do it yourself project had the owner caulking that joint.
A whirly gig is a turbine style vent. When wind pushes on the blades, air movement occurs in the attic creating the air flow needed for ventilating the attic. When they rust, the unit can become damaged. The big problem with this type of ventilation is that the blades will not spin, so then the attic is not sufficiently ventilated. Rust can also cause holes that lead to leaks.
These vents with the little cap that has four openings can pose a problem: what are the venting? On older homes, these could be used for gas furnaces, but they do not meet the current safety standards. They could be venting for mechanical exhaust vents such as in your bathrooms. They may be part of the attic ventilation system. This is why a roof inspection has to include going inside the attic. The big problem with the television dish can be how is the dish attached to the roof, and how is the wire secured to go into the home. A cable running into a vent should not be fished through a furnace vent. The cable should not be nailed into the roof with clamps, where the nails are not caulked. The cable should not be left loose, because the swaying motion of the cable in a windstorm will damage the roof surface. The bolts holding in the dish should be caulked, which often is not the case.
When walls come down onto a ledge or roof surface, we have a flashing piece. Since most flashing comes in a set length, the builder will overlap the pieces. That can prevent some moisture from entering during a rain, but not all. THis joint should be sealed with roof caulk.
There are different methods of ensuring that the flashing lays flat on the roof surface. (Shingles and flashing which do not lay flat can become damaged during windstorms when the wind pushes up on the material from underneath). Most often we see nails used to hold the flashing down. Staples are sometimes seen. In any case where a fastener is used, that fastener should be caulked. If the nail or staple rust, they may move out of the hole that they created, causing a leak point.
The nail does not have to be rusted though to cause problems. In this example, we see another roof to wall flashing where the flashing is not sitting flush to the roof surface. Again the problem is wind. Wind can drive rain underneath the flashing into the wall, or cause the flashing to go farther up, which allows more rain to enter.
When we see a domed vent as in the picture, we are looking at a vent for the attic ventilation system. This may be a mechanical vent, or it may be passive. The mechanical vent has a fan, where the passive is simply an opening. Having fastener heads caulked helps protect them. We also look for rust, and that the flashing is sitting flush on the roof surface.
My preference is to use metal plumbing vent flashing, because they typically last as long as the roof surface, if not longer. This photo demonstrates one problem with them: the opening can be closed off. The plumbing vent allows air into the drainage portion of your plumbing system to ensure smooth flow at the drain. A partially closed vent such as this one does not impede the water flow, but this could be a future problem area. Birds will build their nests on the vents, blocking the opening. AN object flying through the air during a windstorm can complete the job of sealing up the opening, or debris can fall into the opening. These may seem unlikely to you, but I have seen all of these cases happen, so I report on jobs like this one.
One technique adopted by builders to use step flashing from a wall to roof, but to have the stepped pieces of metal to look better, was to use a decorative piece of flashing to cover the step flashing. That is what I thought when I saw this roof from the ground. Once at the roof surface, I realized that I could see behind the brick from a gap between the wall and roof surface where the flashing should have been. During a rain with wind, water could be forced behind the wall.
Condition of the roof covering
Damaged composite shingles can have different problems, but as homeowners, we tend to concern ourselves with the larger picture (does the roof need to be replaced). This is a newly installed roof, so most shingles are in great shape. These shingles have most of the material removed in a small spot. This can lead to further problems with water damage. Roofers can be careless with the packages of the shingles where they cut into the shingle when removing the wrapping. In this case, the damage was probably due to either improper support system used when installing the roof (not using roof jacks) or a roofer walking on the roof with a cleat type shoe.
To create a safe path for workers to go up the roof, we see roofers either using a roof jack or a piece of lumber nailed to the roof surface. The nailed lumber is a bad idea, since it will always leave these holes. Roof jacks are supposed to be slipped under the shingle, with the nail heads under an overlapping shingle. Remember that these holes go down into or through the sheathing, so they make a great path for water, causing a roof leak.
Here we see a roof with quite a few missing shingles. People do not always notice them. I have a neighbor who keeps loosing more shingles from his roof with each high wind day, and he thinks his roof is fine. This situation does not mean that you need an entirely new roof though. You can replace the shingles that are missing. One problem is that if you buy the exact same shingles, they will not look the same due to weatherization. A problem when looking at a home to purchase is that different colors on the roof do not mean missing shingles all of the time; maybe new shingles were installed. The only way to tell is to go up on the roof.
Excessive moisture on one section of the roof does causes problems for the shingles on that surface (I have had this argued that this would not be the case, so I offer this photograph). This is the roof covering over a back door. The home is L-shaped at this point. The upper roof has a valley, which directs a good deal of water onto this lower roof. The shingles are no longer laying flat. The UV protection (small pebbles embedded into the shingle) have worn off of the surface.
Sheet metal screws are used to hold the metal roof down. Sometimes you can find these to be bolts. The problem is the same with nails in other roof coverings: when the screw rusts, leaks can happen. Often on these porch roofs, installers do not caulk the heads of the fasteners, but this step should be taken.
Along the edge of this roof we are seeing damaged shingles. The drip edge which kicks out the water away from the fascia is coming off as well. This home has obtained damage from a windstorm, but installation issues can also be part of the reason. The fascia is not quite damaged yet, but this situation can lead to more damage to the roof covering and the wall below.
This piece of flashing goes by many names, but I choose to use the term kickout flashing, because I find it the most descriptive. This piece of flashing runs along the edge of the roof going underneath the roof covering and over the fascia. Rain water is kicked out from the fascia surface, thus avoiding some moisture problems. In these photos we see that the flashing is not sitting flush against the fascia or trim piece on the fascia. This does allow for some moisture to get behind this flashing. This can also be a problem with some pests coming into the attic.
Have you seen a roof where the shingles are not all flush? You can see some sticking up. Here is a picture of the culprit: a nail holding the shingle below the one sticking up is popping up from the surface. This can damage the shingle coming up, or it could be a source for a moisture leak.
It may not be that the nail is popping up, but that we have a different type of fastener causing the shingle to lift. Here we see a tab that holds the shingle down onto the sheathing better that just a nail, but part of the tab is lifted, so the shingle has a gap for the wind to lift it up more.
The culprit in lifting the shingle up here was not a fastener, but the installation method. The shingle was curving up because the ends are being pushed on. As with the fastener, lifting the shingle allows wind and water underneath the shingle.
Tree branches growing onto the roof surface can be a problem in windstorms too. As the branches sway, the surface of the roof becomes damaged. I have seen where branches have not only damaged the roof covering, but they took off everything, leaving the framing exposed.
A composite shingle comes in layers. A roof surface with quite a bit of damage is obvious, but we should be looking for damage to the surfaces of these shingles early to prevent leaks. Here we see that a small section of the shingle is discolored, which is due to the top surface being worn away. Once this wearing away process has begun, the shingle will continue to deteriorate. One thing to consider is that when we see the first shingle with surface deterioration, we may be finding more soon.
In both of these photographs, we see where different roof designs go from a sloped roof to what is more a flat roof. Leaf debris ten collects at the roof valley and roof intersections. One roofer told a client of mine not to worry, you have a rof that can withstand the leaf debris. The problem is that these piles becomes nests for pests that can damage your home; they hold water causing moisture problems; and they help to deteriorate the roof surface faster.
Sometimes we simply see bad roof designs. The two photos above are due to flatter roofs added over a porch and an extension of the home. In this photograph, the home has a higher roof surface in the middle and lower roof surfaces on the sides. A chimney comes up halfway through the lower roof and halfway through the upper roof. A collection point was created, where leaf debris does not quickly clear out. Now we have moisture damage in the wood covering of the chimney. Having a piece of flashing or a small half saddle (a bump in the roof) would divert leaves and moisture away from this area. There are many different roof designs which either funnel a massive amount of water to a small location, or create a small channel that will catch the debris to hold it in one place.
There are a few places where nails or other fasteners are exposed in a roof surface. These should be sealed with an appropriate substance, such a silicone caulk made for a roof application. I have seen silicone used that was not meant for a roof application with the idea that all silicone caulk is the same. If not made for a roof application, the caulk will break down faster. One area where nails are not caulked is under an existing shingle, since that shingle protects the nail head. With damage to the shingle, these nail heads can become exposed. Sealing these nail heads is needed. Maybe a roof caulk will be a good quick fix; the better option is to replace that shingle. Builders and some roofers will leave extra shingles on hand for such occasions.
While on a downtown balcony, I snapped this photograph, because I found it inspiring. This roof brings a lot of interest to this building, and it is done in metal. We have a quansat semicircle roof passing through a stepped roof. Metal roofs can be energy efficient, and they can be interesting.