The exterior layer of a roof is often the one homeowners give the most attention to. Is it durable? Is it long-lasting? Does it have aesthetic value? These are important questions. However, in practice, when rain hits your roof, the outer layer isn't the only one that matters. The outer layer takes the brunt of the storm, of course, but the layers underneath are essential too.
A typical roof has two layers between the shingles and the rafters. The rafters support the roof deck, or sheathing. This layer is often made of plywood or OSB. Above that, roofing felt or membrane lies just under the shingles. Both of these layers can lose their structural integrity when they suffer water damage. However, how can you tell if your roof has a moisture problem?
This guide lists three signs you have a moisture problem under your roof's outer layer.
1. Displaced or Damaged Shingles or Tiles
Any shingles or tiles that are crooked, missing, slipped out of place, lifted at the edge, or otherwise compromised can be an easy avenue for water intrusion and subsequent water damage. This is why, after storms, you need to check your roof over carefully for even minor damage.
However, a storm isn't the only possible cause of this type of problem. Any damage you find needs to be treated as a potential leak. For example, if you have concrete roofing tiles and one of them has gradually slipped down and out of the correct position, you can't assume the damage is recent.
The tile may have slipped gradually over days or weeks before you noticed anything was amiss, and the entire time it could have been letting the elements access the underlayment. The underlayment, and even the sheathing beneath, could be rotted out. Be sure to have the damage inspected by a professional contractor.
2. Mold, Wet Insulation, or Rusted Fasteners
Condensation that collects on the underside of the roof can cause water damage to both the sheathing and the felt underlayment. However, just because you have a condensation problem doesn't mean you'll necessarily see condensation when you go up to the attic to check. You may see some, or you may not if your condensation problem is seasonal or nocturnal.
However, you can still look for visual clues that a condensation problem is occurring. The roofing fasteners may be rusted where they stick through the sheathing, or the sheathing itself may have watermarks. In addition, you may see insulation that is wet or looks pockmarked from condensation dripping onto it. Mold is also a dead giveaway of a moisture problem.
3. Blocked or Missing Vents
Technically, blocked vents tend to be a cause of a moisture problem rather than an effect. However, if your roof vents are blocked, then the moisture that rises to your attic from your living space isn't able to escape and therefore causes moisture problems for the underside of your roof. The extent of the problem may vary based on the amount of moisture present.
Inadequate ventilation will cause even worse problems if you have a damp basement, naturally humid air in your region, rain leaks in the roof or walls, or some other added source of excess moisture. After evaporating, this moisture is carried by warm air up to the attic, where it will condense on the cooler underside of the roof at night.
These three signs should all alert you to the potential for moisture damage in your attic, whether that's from condensation and humidity or a rain leak. If you need a professional roofing contractor to repair water damage, find and remediate a leak, or help add or enlarge attic vents, give Residential Roofing Services a call today.