Unusual amounts of snow lead to many things—stalled cars, snowball fights, and airport closings. They also lead to many homeowner concerns over the roof’s ability to hold the weight. Find out what you can do to identify or prevent problems.

When weather stations predict frigid temperatures and record snowfall, concerns rise that roofs may not make it the full season but instead collapse under the strain of a surprising snow load. If it’s your first winter with your current roof (new or old), you may be trying to assess the situation for the season. How much snow can a roof hold, anyway? And are there steps you can take to avoid a worst-case scenario?

How much snow a roof can hold depends on the type of snow, roofline, and material, among other considerations.

These questions aren’t quite so easy to answer, because there are several variables at play. At the top of the list are the following:

· The weight of the snow. Wet snow can be nearly three times heavier than dry, fluffy snow. So, while a cubic foot of fresh powder might weigh in at 7 pounds, that same amount of wet, packed snow could be more like 20 pounds.

· Your roof’s structural design. Generally speaking, steep and smooth roofs shed snow more easily than flat or only slightly pitched roofs.

· The roof material. Choose a strong, durable set of shingles like asphalt or slate. While both do well to support the weight of snow, asphalt shingles are a more affordable option and easier to replace if necessary.

Ultimately, what amounts to a dangerous accumulation of snow on one roof would be just fine on another roof down the block. If you’ve had a new roof installed during your time of ownership, consult the supplier and/or roofing contractors who did the work to get a professional opinion. If not, you may wish to schedule a roof inspection to ascertain more detail on the condition of your roof.

Looking for the warning signs of a weak roof.

While you can draw some conclusions by looking at your roof from the curb, it’s indoors where you’ll find the most instructive clues to a potential problem. Head up to the attic and examine the rafters for any noticeable bends or cracks. If you find anything that gives you pause, bear in mind that it’s not necessarily (and most likely isn’t) a sign of impending roof collapse. There are many possible explanations for damaged rafters—for example, termites. And even if snow is to blame, you may be looking at damage from a previous winter. In any case, ask a licensed structural engineer to evaluate the problem promptly.

Elsewhere, particularly on the upper floors, toward the middle of the house, keep an eye out for new cracks in the drywall or plaster surrounding interior door frames. If those doors are suddenly sticking when they used to open and shut with ease, this could be an indication that the frame of your house has shifted due to a structural issue. Again, wall cracks and sticking doors are not causes for panic; rather, they are reasons to seek out the advice of a licensed professional.