When you’re researching the best installation, design, and materials for your new roof, you can’t stop at surface level knowledge. In fact, many roofing contractors, even experts, can disagree about which roofing techniques are likely to be the best and most cost-effective, and you may need to dig deeper to discover what’s best for your roof.
Here are a few controversies you may discover as you research your next roofing project.
1. Drip Edge Flashing Installation
Drip edge flashing, although inexperienced roofers may not install it at all, can cause disagreements between and even confusion among experienced roofers. Should the drip edge be installed over the ice and water shield (also known as ice-barrier membrane), or beneath it?
Building code and product manufacturers may differ in their recommendations for how to layer these items during installation. This variance can feed into the confusion. Although building code requires ice and water shield to overlap the drip edge, some drip edge manufacturers say the drip edge should be installed over the ice and water shield.
This reversal allows for better protection in the case of an ice dam. If water overflowing from the gutter comes up over the drip edge flashing, it won’t be able to leak under the membrane if the drip edge flashing is above the membrane.
You can also opt to install membrane both above and below the drip edge, which both offers maximum protection and complies with building code.
2. How Much Ice and Water Shield to Use
Ice and water shield is a type of underlayment that’s waterproof. This may sound like a great thing for your entire roof since it can provide an entire extra layer of weather resistance beneath your main roofing material. And indeed, some contractors feel that (depending on the roof) using ice and water shield over the entire roof can be productive.
However, other experts feel that ice and water shield should be confined to the edges of the roof for two reasons. First of all, an entirely waterproof underlayment doesn’t work well with many residential roofing systems, since it doesn’t allow water vapor or air to pass through. This can lead to a buildup of condensation on the roof deck, leading to a moisture problem.
In addition, ice and water shield has an adhesive backing. So when you need to replace it, the tear-off process can be very expensive because it takes a lot of labor hours if you have it adhered to your entire roof deck.
However, keep in mind that even if you’re confining ice and water shield to leak-prone areas such as the edges of the roof, you may need a lot more of it in climates that get a lot of ice dams. For instance, some states have building codes that require the shield to extend two feet in past the outside wall of your home.
3. Whether to Tear Off or Overlay Your Roof
Tear-off versus overlay is another controversial subject among roofing contractors. A tear-off is a roof installation that involves removing all the old shingles and underlayment first, whereas an overlay involves placing new shingles on top of your current shingles.
Some experienced contractors believe that since an overlay roof has a shorter lifespan and can conceal damage to the roof deck, they can’t, in good conscience, recommend an overlay roof. Other drawbacks they may point to include adding weight to the house and difficulty in tracing leaks.
However, other roofers feel that the benefits offered by a roof overlay (which mainly include a more affordable installation due to avoiding the labor costs of tear-off) are a reasonable tradeoff, especially if the roof deck isn’t suspected of having any damage.
While roofing contractors don’t agree on every issue, you can get to the truth behind the controversy by doing a little research of your own and discussing the issue with your roof contractor. For more information about roofing techniques and options for your next re-roofing job, contact Jerry Newman Roofing & Remodeling Inc today.