The Chilling Consequences at Winter

As winter’s icy grip tightens across Scotland, homeowners find themselves grappling with the harsh realities of sub-zero temperatures. While many focus on keeping their interiors warm, it’s essential not to overlook the potential impact of these extreme conditions on the exterior of your homes. One critical component that bears the brunt of winter’s wrath is the roof. Sub-zero conditions can pose serious challenges to the structural integrity and performance of a roof, leading to various issues that demand attention and preventive measures.

Freeze-Thaw Cycle

One of the primary concerns during sub-zero conditions is the freeze-thaw cycle. In Scotland, we often get freezing nights and slightly warmer days. As temperatures fluctuate, water can seep into the smallest cracks and crevices on a roof. When this water freezes, it expands, exerting immense pressure on the roofing material. The subsequent thawing can lead to the creation of even larger openings, providing an entry point for more water during the next freeze. This cycle can compromise the structural integrity of the roof over time, resulting in leaks and other serious problems. If there are an average of 50 days of the year that are sub-zero, that is 50 days of potential freeze/thawing that can damage your roof.

Ice Dams

Sub-zero conditions contribute to the formation of ice dams, a phenomenon that occurs when snow on the roof melts and refreezes at the eaves. The melted snow can’t drain properly due to the refreezing, causing the formation of ice dams. These dams can damage shingles, gutters, and other roofing components. Additionally, the trapped water behind the dam can find its way into the attic, leading to water damage and mould growth.

Snow Accumulation

While Glasgow doesn’t get much snow these days (Beast from the East excluded), heavy snowfall is common in sub/zero conditions and in the Town’s and Villages in the Central Belt of Scotland, this can be a problem. The weight of accumulated snow on a roof can be substantial.

Roofs are designed to handle a certain load, but excessive snow accumulation can exceed this limit. This added weight can lead to sagging, structural damage, or even a roof collapse in extreme cases. Regular removal of snow (where safe to do so) from the roof, especially in areas prone to heavy snowfall, is beneficial to prevent such issues.

Flat roofs that have already suffered from ‘ponding’ can become an issue with heavy snow build up.

Material Contraction

Extreme cold can cause roofing materials to contract. While modern roofing materials are designed to withstand a range of temperatures, prolonged exposure to sub-zero conditions can impact their flexibility and durability. Shingles may become brittle, losing their ability to seal properly and protect against water infiltration. Metal roofs, though durable, can contract and expand with temperature variations, potentially leading to issues like loose seams and fasteners.


Condensation is another concern during sub-zero conditions. Warm air inside the house can rise and come into contact with a cold roof surface, leading to condensation. Over time, this moisture can contribute to the deterioration of the roof’s structure and insulation. Proper ventilation and insulation are essential to minimise the risk of condensation-related problems.

As winter descends on Scotland with its sub-zero temperatures, homeowners must be vigilant about the potential consequences for their roofs. Regular inspections, prompt repairs, and proactive measures such as adequate insulation and ventilation can help mitigate the impact of subzero conditions. By addressing these issues head-on, homeowners can ensure the longevity and performance of their roofs, protecting their homes from the chilling effects of winter.

At Balmore, we have 40 years of service helping customers maintain and repair their roofs after winter temperature drops and storm damage. We have decades of experience on the matter and are always wanting to help our customers get the most from their roofs. So if you need help ensuring that your roof is ready for the winter months ahead, call our Glasgow head office today.