Frequently Asked Questions

We offer a premium quality hand nail option!

Nail guns are popular because they shorten training time and reduce effort. It takes years of practice to become proficient at hand nailing, but nail gun productivity may be achieved almost immediately. In spite of the productivity advantages that gun-nailing offers, we still offer a hand nailing option for our highest quality installations.

On structures built prior to about 1960, roof sheathing boards are typically 5-1/2″ wide. Plywood and OSB sheathing have been much more commonly used on structures built after that time. When installing shingles over relatively narrow 5-1/2″ boards, many nails will be unintentionally driven between the boards. If not pulled out and re-located, these nails will back-out over time. When hand driving a nail between boards, the installer can feel the nail “missed”, and can use the claw of their hammer to pull the nail out. This feel is much more subtle when using a nail gun, ad nails driven between boards are more likely to be overlooked, later causing raised shingles or leakage.

Ideal nail placement is limited to a very small area on most shingles. When a nail is driven outside of that area, the shingle’s wind resistance and resistance to slippage is reduced, and the manufacturer’s warranty may be invalidated. Proper nail placement may be achieved with either nailing option, but is more easily achieved when hand nailing.

In addition to being properly located, nails must be driven flush with the surface of the shingle. Nails should not be over-driven or under-driven. Variables affecting this requirement include temperature, variations in wood type, and the differing types of roofing and flashings that are being secured. Nail gun air pressure must be adjusted to compensate for these variations, often requiring a trip to the compressor for adjustments. Hand nailed installations are less apt to suffer from under-driven or over-driven nails.

Nail guns are currently utilized in the great majority of shingle installations, and the associated cost savings often make this the reasonable choice. However, in other situations, especially over narrow sheathing boards, we continue to specify and recommend hand nailing.

“Ice dams” are accumulations of ice that prevent normal drainage from a roof, potentially causing heavy interior leakage. These types of leaks are made possible by heavy snowfall, followed by outdoor temperatures that remain below freezing for extended periods of time. Heat loss from the building interior causes the snow to melt, but the melted snow re-freezes at the colder overhangs and gutters. This cycle of melting and re-freezing continues as long as temperatures remain below freezing, causing “ice dams” to grow. Eventually, the “dam” causes drainage to back-up beneath the roof, and enter the structure.

Weather conditions in the Cincinnati area were conducive to “ice dam” formation in February of this year (2022), February of last year, and in the winters of 2014 and 2010.

Leakage occurring during the conditions described, may be identified as resulting from ice dams if the leakage does not reoccur during normal rainfall. Once identified, ice dam leakage may be addressed in a number of ways:

• Do nothing. If leakage was minor, and has never occurred in the past, it may be reasonable to decide that the expense involved with possible remedies is unnecessary. Icicles hanging from gutters or downspouts are not generally and indication that repair work is needed. We may be of assistance in determining whether work is needed if you send a photograph of the ice formation to office@molloyroofing.com.
• Improve attic ventilation or attic insulation. For the ice dam to form, snow on the roof must first melt, in spite of the fact that outdoor temperatures are below freezing. Both attic ventilation and attic insulation serve to reduce possibility of rooftop snow melting prematurely.
• Install Ice and Water Shield beneath shingle, slate, or tile roofing. This material creates a barrier to ice dam leakage, and is most economically installed during the course of roofing replacement.
• Install heating cables. There are some ice dam situations that cannot be resolved by anything other than heating cables. Electrical outlets must often be added to serve the new cables. It is often necessary for someone to remember to activate the cables when weather conditions warrant.

Molloy Roofing has worked in the Greater Cincinnati area for well over a century, and in recent decades we have noted an increase in the frequency of ice dam conditions occurring.

The decision to recover or tear-off existing low slope roofing will influence the cost, performance, and insulating value of new roof installations.

“Recovering” the existing roof significantly reduces the cost of roofing replacement and preserves existing insulation value. This approach often provides the best value, but can prove to be a costly mistake if certain conditions are overlooked.

Building codes have long prohibited the installation of more than two layers of roofing. This limitation reduces the likelihood of overloading and of moisture entrapment. While the consequences of overloading may be obvious, moisture entrapment can be equally destructive since trapped moisture will accelerate the deterioration of new roofing, insulation, and even the supporting deck. Core samples provide the information for evaluating existing roofing.

Other factors can influence this critical specification, but trapped moisture is often the most important consideration when assessing the need to remove an existing roof.