Roofing

In order to get your next roofing project off to a good start, be it minor repair or total replacement, the following is a list of items to discuss with your contractor to help ensure both parties are on the same page prior to starting the work. Reviewing some of these key items prior to job start-up will help both parties understand what is expected and hopefully make the job go a little smoother.

1. Review scope of work with the contractor to make sure everyone understands what work will take place. Ask if possible change order items are anticipated and what the unit costs may be for additional work.

2. Understand what the contractor’s anticipated start and completion dates are for the entire job. Knowing the working hours and if weekend work will be allowed is also important

3. Identify storage, parking and work areas. Make sure the contractor understands his responsibility for keeping the areas clean and maintaining the security of his equipment and materials.

4. Make sure the contact person in the field as well, as the responsible person in the office, is identified in case problems arise. Have a list of all emergency numbers of key personnel prior to starting work.

5. Clarify whether the contractor will utilize certain facilities (such s water, electricity and/or restrooms) while working on the job.

6. Bonds, insurance certificates, building permits or any technical submittals should be obtained prior to starting work. The Contractor should be responsible for securing any state or local permits or inspections.

7. Inspect property and document any existing damage prior to starting work to help protect all parties.

8. Understand who is responsible for connection or disconnection of mechanical systems.

9. Find out what warranties will be given from the contractor and/or manufacturer.

After observing and investigating the affects of wind-related roof damage at several buildings this past year, we feel it important to raise a few items to consider when replacing a roof.

*Directly adhering roof membranes to paper-faced polyisocyanurate insulation should be avoided wherever possible. In many of the wind-damaged roofs we’ve investigated, the membranes were applied directly to the insulation and the facer was delaminated from the board, essentially leaving the membrane detached. Loose membranes can be readily lifted, distorted or worse, blown off entirely, in even moderate winds. The use of a proper cover board between the insulation and the roof membrane can help prevent this.

*Warranties should be carefully considered before a system is selected. Manufacturers’ warranties frequently exclude damage from wind above a given speed and that speed is often much less than building code design requirements. As an example, we recently reviewed a warranty that did not cover damage from winds greater than 65 miles per hour, although the roof was installed on an oceanfront building where the design wind speeds are 130 miles per hour. This limitation is roughly half what is to be designed and is well within the “regularly” experienced wind conditions. Therefore, the warranty coverage related to wind in these cases is extremely limited or even non-existent.

*Many roof material manufacturers have added self-adhered membranes to their product lines. While there are advantages with self-adhered products, surface preparation is critical and adhesion is greatly affected by temperature. The use of primers can help with the bond.

It seems that weather is becoming more severe and there’s no reason to think that trend is going to change.  Prior to June 2012, few people had ever heard the term “derecho”, much less lived through one. It’s impossible to anticipate every eventuality and no way to practically design for them.   However, consulting a roof professional when replacing your roof can help avoid these and other pitfalls.

Roof fasteners are probably not the first things you’d think of with respect to energy loss. The photo above was taken on a snow-covered roof and each of the black dots you see corresponds to a fastener and washer used to secure insulation, through which enough heat was lost to melt snow.  They aren’t very big (about two inches in diameter), but there are a lot of them.
The subject roof assembly consisted of an EPDM (rubber) membrane directly adhered to a layer of mechanically attached polyisocyanurate insulation, without a cover board.  Cover boards are not usually required by manufacturers of thin single-ply membranes, such as EPDM, PVC, and TPO, although they should be.
An insulating cover board installed between the primary insulation and the membrane not only helps reduce energy loss (heat loss during the winter and gain during the summer) it reduces the chance of condensation forming on the fastener plates during cold weather.  Such condensation can cause the membrane to become debonded at the fastener heads.