Common Roof Questions

What is the best roof?

Wouldn't it be great if there was one answer to all our roofing troubles? Unfortunately there is no magic bean in the roofing industry that solves all roofing problems. What the roofing industry does offer is a wide variety of good products from alot of different roofing system manufacturers, each having attributes and faults. The key to selecting a proper roofing system is identifying the specific roof design needs of your building, and how each roofing system meets those needs. A simple example would be: If a building has very heavy foot and wheel traffic on the roof, a 45 mil single ply membrane probably would not be advisable, due to its limited puncture resistance.

Why does my roof leak?

Well a cynic might answer that there are two kinds of roofs, those that leak and those that will leak. Roofs leak from a break in the waterproofing layer, sometimes caused by mechanical damage (ie, someone dropping an HVAC access panel on the roof), sometimes from an opening in the sealant, such as pitch pans and caulking, high winds and hail damage and sometimes from deterioration or defects in the roofing material. The key to roof management is leak avoidance. Find and correct defects before they leak because once it does the damage will only spread comprimising the whole roof subroof integrity (wood rot and mold).

How long should a roof last?

Like any building component, roofs degrade at different rates depending on a large number of factors: the quality of original construction, the level of abuse, the level of maintenance, appropriateness of design, etc. So how long should a roof last? We have seen poorly designed and installed roofs go as few as six or seven years before they failed, and we have seen old coal tar built up roofs that were over 60 years old. Most building owners, roofing contractors and designers feel 20 years is an acceptable service life.

Can I cover over my existing roof?

Installing a roof over the top of an existing roof is generally acceptable under these guidelines:

• A building cannot have more than two roof layers
• No wet insulation can be left in place
• The roof structure must be able to handle the additional roof load
The new roof must be attached to the roof deck to meet wind loads (it is not generally acceptable to adhere the new roof to the old roof).

How many roofs can I put on?

Most building codes allow a structure to have two roof membranes in place, but not a third. The codes are also now requiring all roof layers to be removed once the two roof limit has been reached, when looking to install the third roof.

When is the best time to put on a new roof?

This question could be interpreted two ways, so we'll answer each question.

1. What time of year is the best time to install a roof
   The optimum time to install a roof is when the temperatures are above freezing and the wind and rain are at the lowest intensity and frequency. This allows the roofer the best conditions for installation, with the fewest interruptions and lowest risk of leaking. Unless you are very fortunate, sometimes you cannot schedule the roofing work during these periods, and you may need to install the roof in cold temperatures, or in the rainy season. If you know this in advance, it may be possible to choose a roof system that is more tolerant of inclimate weather.
2. The second question might be put this way: "How do I know when my roof has failed?" Different roof types fail at differing rates and with different failure modes.

Without going into a long dissertation, the several general failure clues are:

• Does the roof leak in numerous locations?
• Do leaks continue, despite repeated repair attempts?
• Do repairs seem to make leaks worse, or do new leaks develop after repairs?
• How tolerant is the occupancy to leaks? Low leak tolerance generally means the "failure" decision is reached earlier.

It is generally better to reroof at the appropriate juncture, rather than pouring money and time into ill advised repairs, but there are exceptions.

How much does a new roof cost?

How much is a new car? Well, the answer to both questions is, "That depends." We find the cost of reroofing is less dependent on the type of roof membrane, than the project's relative size (large projects cost less per SF than small ones, building height (tall buildings cost much more than short buildings), number of roof penetrations (more penetrations = more money).

In our recent project bids, our roofing costs ranged between $3.15 per square foot and $53.00 per square foot. Does that narrow it down?

How often should my roof be inspected and by whom?

We recommend a thorough inspection every two years by a roofing professional, with "walkover inspections" by plant or building maintenance personnel at least twice per year. Roofs that are heavily trafficked or generate roof debris (paper companies, food processors, etc.) may require more frequent inspections. Roofs with many penetrations and lots of roof traffic are going to require more frequent maintenance than roofs with no penetrations and low levels of traffic. There are a number of "musts" on every roof however, including keeping drainage devices open and clear of debris, removing foreign objects, and conducting regular inspections. Some roofs require more maintenance than others, and each should have a maintenance/inspection schedule.

Which roofing manufacturer should I use?

There are a lot of things to consider when choosing a roofing manufacturer. Do they offer the roof membrane/system that best fits your needs? Is their product quality the best of that generic type? What is their commitment to after-the-sale service? Some of the best products and service come from mid-size or smaller companies.

How do I get a fair quote and a good contractor for a new roof?

As self-serving as this sounds, a knowledgeable roof consultant can steer you through the many pitfalls of buying a new roof. With their help, you can pick the right roof system, communicate your design intent through project specifications, and bid to qualified contractors. The good contractors appreciate bidding well designed roofs, and bid with confidence that no one will "backdoor" the project and bid something not otherwise specified.