Hot Afternoons Soften Shingles, So Name Who Walks the Roof

A St. Louis July can put a dark asphalt shingle surface well past 140 degrees Fahrenheit by early afternoon, and the shingle is not built to be stood on at that temperature. If your roof is being replaced in the summer, the material question is no longer only which shingle you pick. It is also how the bundles are staged, when they are carried up, and who walks the slope while the sealant strips are still soft. Those choices belong in the spec, and a homeowner who asks about them before the first bundle goes up is in a better position than one who finds out from a scuffed tab in September.

Why heat changes the handling

An asphalt shingle is a mat coated with asphalt and topped with mineral granules. The asphalt keeps the shingle flexible and holds the self-sealing strip that bonds one course to the next. When the asphalt is warm, it gives. A heel dragged across a warm tab can crease it, and a bundle set down on a hot deck can press granules into the surface. None of this shows from the ground. It shows later as bare patches, lifted corners, or a tab that will not lie flat once the weather cools.

The sealant strip is the second part of the problem. Shingles are made so the strip on one course bonds to the course above it after a few sunny days. In heat, that bond can form faster than the crew expects, which is why a shingle that is slid into place or pulled out of position can tear the strip. In cold weather the opposite happens, and a separate sealing step applies. Summer is the season where handling matters most for the sealant, because the bond is ready to form before the work is finished.

Material and spec

Name the handling in the spec, not only the product. Atlas and Malarkey shingles carry install instructions on the wrapper and on the install sheet inside the bundle, and those instructions are the baseline the crew should follow. A spec line that says the crew will install per the printed instructions, with no more detail, leaves the summer questions open. Four items are worth writing down.

• Where the bundles sit while the crew works. A bundle left in direct afternoon sun on a dark roof gets hotter than the air around it, and the wrapper alone does not prevent that.
• How the bundles go up. Carrying them by the strap or the top edge, rather than dragging them across the deck, keeps tabs from folding under weight.
• Where the crew walks. Working from the eave up on the nailed course, rather than across fresh courses, limits scuffing and heel marks in heat.
• When the crew stops. Some roofers stop during the hottest part of the afternoon. Others keep going. The spec should say which, and what happens to an open section if they stop.

Two of those points are about the crew, and two are about the material. That is deliberate. The shingle does not care who is on the roof, but the damage a shingle takes depends on the people who walk it and the sun that warms it. A spec that names the material and not the handling can be followed to the letter and still produce a roof with marks on every slope.

The sealant itself also needs a line. If the roofer intends to hand-seal any tabs, the spec should say which tabs and with what product. Hand sealing is most often a cold-weather step, but a few tabs can lift on a windy summer afternoon, and the roofer should know the plan for those before the crew is on the roof.

What it costs

Heat handling does not usually appear as its own line on a roof bid. It shows up in labor pace, in crew hours, and in whether the bid assumes an afternoon stop. A crew that stops at midday will take longer to finish the same roof than one that works straight through, and that difference belongs in the schedule. Ask whether the bid assumes a midday stop, and if so, how many hours it adds. A roofer who says there is no effect on time should be able to explain where the hours go.

Shingle waste is a second cost. Bundles that are scuffed, creased, or cracked on delivery day are not always replaced without a question. Ask who pays for a bundle damaged on the roof, and whether the order includes spare shingles for repairs. That question belongs with the material spec because it decides whether a damaged tab can be swapped or whether the damage stays in the roof.

Summer installs also change the scheduling risk. A roof started in late July that runs into an August storm can be left with an open deck. The cost of that comes from the weather day and tarp terms in the contract, not from the shingle price. For the spec, the main point is that the bid should say what the crew does on a hot day with an open deck and a storm forecast, and who supplies the tarp if one is needed.

What to ask

Before the first bundle is delivered, ask the roofer these questions, and write the answers into the contract.

1. Where will the bundles wait on the day they arrive, and will they sit in shade or in direct sun until they go up?
2. Will the crew stop during the hottest part of the afternoon, and if so, how many hours does the bid assume it loses?
3. Which path will the crew use to walk the slope, and will they work from the eave up on each course?
4. Who replaces a shingle that is creased or scuffed during install, and is any spare stock included in the order?
5. If a storm is forecast before the deck is covered, what does the crew do, and who supplies the tarp?

If the answers are vague, that is information too. A roofer with a plan for heat usually describes it in the same plain terms used for nail counts and drip edge. A roofer who answers with "we have done this for years" has not told you what the crew will do on the roof on a 95 degree afternoon.

Call the office at (314) 220-2333 if you want to talk through the summer schedule before you sign. Ask for the material spec with the handling lines written in, and keep the install sheet from the bundle in your file.