TSW Roofing Solutions, Inc., Roofing Contractors, Forest Hill, MD

Roofing FAQ

Our Roofing FAQ will help you make informed decisions whenever you have roofing problems.

Roofing’s primary purpose is to shelter the building from rain, snow, and sun. Roofing also provides thermal protection. If your roof needs to be repaired or replaced, or if you simply want to understand the results of your roof inspection and the importance of preventive maintenance, read our Roofing FAQs to learn more about your roof. 

What is a roof system?

Very simply, Roof System refers to the three major components of a roof: Decking (the wood base), Underlayment (felt paper; leak barrier), and Covering (slate, asphalt, or wood shingles; tiles; metal; rubber, etc.). The slope (or pitch) of the roof can determine the types of materials used for the decking, underlayment, and covering. Slope is a ratio based on the rise (vertical measurement) to the run (horizontal measurement, generally based on 12 inches) of the roof. For example, a roof slope measuring under 2/12 (or 2 inches rise per one foot run) is considered flat and cannot use shingles. Roof slope between 2/12 and 4/12 requires low-slope application techniques to avoid leaks. Standard slope is 4/12 up to 21/12. Roof slope above 21/12 requires steep-slope application techniques. A professional roofer will make sure you understand the need for specific application techniques based on roof slope. 

How often and when should I have my roof inspected?

An annual inspection will reveal any corrective action that should be taken to prevent small issues from becoming disasters. Even a small leak can damage the insulation and interior framing, and may cause rot and mold to develop in walls or attics. Inspections can be done at any time of the year, unless there is snow or ice on the roof. In fact, spring is a great time to check for snow and ice damage to your roof system.

How long will a slate roof last?

Slate roofs have been among the world’s finest roofs for thousands of years. Slate is a natural, quarried product that is dense, durable, and essentially nonabsorbent. The region where it was quarried determines the life expectancy of roofing slate. Softer (S2 or S3) slates may last about 55 years to 100 years. Harder slates can conceivably last centuries on a properly maintained roof. Here are a few more facts about slate: Natural cleavage allows slate to be split in one direction, with the length running in the direction of the grain. Depending on the rock from which it was quarried, some slate splits to a smooth, fairly even surface texture, while other slate is rough and uneven.Chemical and mineral composition determines slate’s color. Slate whose color changes minimally from exposure to weather is known as permanent or unfading slate. Slate that shows a more noticeable color change is known as weathering slate.

Is there an advantage of hiring a roofing company that specializes in slate roofing and repair?

A properly installed slate roof is more than a covering—it’s also an enduring work of art that requires a particular skillset and toolkit. Slaters are specialists who are trained to install and repair slate and copper products. They have the right knowledge, experience, and tools to repair or replace your slate roof and deliver the best results possible.

Snow is sliding off of my slate roof and on to my walk way. What can be done to stop this?

Unlike shingle roofs, the surface of slate roofs is fairly smooth. Large sheets of snow may slide off the roof as the surface below heats up, which can be either a minor nuisance or a potentially dangerous situation, depending on where the snow falls. The solution is to install snowguards that are designed to hold the snow on the roof, where it can melt and drip safely.

How long will the shine on my copper last?

Copper will begin to lose its shine after the first rainfall and will continue to change until it reaches a light blue-green color.This patina on the copper will actually increase the lifespan of copper gutters, roofing, and flashing by protecting them from atmospheric corrosion.

What are the advantages of an asphalt shingle roof?

Asphalt is the most common roofing material in the United States, mostly because it is less expensive than other roofing materials. Depending on the quality of the shingles and the workmanship, an asphalt shingle roof should serve you well for approximately 15-20 years. Although a shingle roof does not require a lot of maintenance, it should be inspected annually and repaired as soon as a problem is noted.

I’ve been told I need a new roof. Can I just put new shingles over the old ones?

Professional roofers usually do not recommend this practice. Tearing off the old roof reveals any existing condensation problems, leaks, defects, and areas where waterproofing has failed. It is always better to correct rather than cover the problems.

What covering is suitable for a flat roof?

Because a flat or low-slope roof is nearly horizontal, it must be covered by a waterproof membrane. Ethylene Propylene Diene Monomer—EPDM—is a durable synthetic rubber compound used most commonly now for new and reroof applications on flat roofs. You can find much more information about EPDM for roofing on the EPDM Roofing Association website at http://www.epdmroofs.org/.

Where can I find more information about choosing a roofing contractor and materials?

For much more information on slate roofing than we can provide here, visit the National Slate Association.

For consumer-oriented educational videos and brochures about roof systems, visit CertainTeed’s online Learning Center.


Why are vinyl windows supposed to be better than my old aluminum windows?

Vinyl windows are designed specifically to make your home more comfortable and reduce your energy costs through more efficient thermal protection. Vinyl windows are made primarily from polyvinyl chloride (PVC), a material that is nearly maintenance-free and which retains its new look over a long period of time. Manufacturers make their vinyl windows from a custom compound (similar to a recipe) that defines the windows’ performance over time. Each additive to the compound, along with each design element, contributes to the windows’ durability, heat resistances, insulation factor, and other essential characteristics. Vinyl windows can also be custom made for a precise fit. Besides being easy to manage and clean, they will enhance your home’s beauty.