How to prepare your roof for winter
A guide to roof paint and waterproofing
Winter can be hard on roofs. Heavy rain, strong winds, freezing temperatures and standing water can all expose existing weaknesses, turning a small crack or damaged area into a much bigger problem.
Taking time to inspect and prepare your roof before winter arrives can help prevent water ingress, protect the underlying structure and extend the service life of the roof. For suitable roofs, applying the right roof paint or waterproofing coating can form an important part of this preventative maintenance.
Whether you are maintaining a domestic garage, extension or outbuilding, or looking after a commercial or industrial property, this guide explains how to prepare your roof for the winter months.
Why prepare your roof before winter?
A roof that appears sound during the summer can become vulnerable when exposed to months of wet and changeable weather.
Rainwater can find its way through cracks, splits, failed joints and other weak points. On flat roofs, standing water can make existing defects worse, while moss, algae and accumulated debris can retain moisture against the surface.
Cold temperatures can create further problems. Water entering cracks and damaged areas can freeze and expand, potentially making existing defects larger.
Preparing your roof before winter gives you the opportunity to identify and deal with these problems while conditions are more suitable for maintenance and coating.
Inspect your roof for signs of damage
The first step in preparing your roof for winter is a thorough inspection.
Look for:
- Cracks, splits and holes
- Damaged or deteriorating roofing felt
- Blisters or areas where the existing coating has lifted
- Failed joints and seams
- Gaps around edges, gutters and roof penetrations
- Areas of standing water
- Loose or damaged materials
- Moss, algae and other organic growth
- Signs of previous water ingress inside the building
Pay particular attention to areas where different materials meet and around gutters, valleys, roof edges, outlets and penetrations, as these can be vulnerable points for water ingress.
If you identify a structural problem or significant damage, a suitable roofing professional should assess it before applying a coating.
Clean and prepare the roof
Good preparation is essential when applying roof paint. Even a high-performance coating can fail prematurely if it is applied over a contaminated, unstable or unsuitable surface.
Remove leaves, dirt, loose debris and other contamination from the roof. Moss and algae should also be dealt with before coating. Use the appropriate fungicidal cleaning products for removing organic growth, helping to prevent it from growing beneath a new coating.
Any loose or degraded material should be removed and damaged areas repaired before painting.
The roof should then be left in the condition specified by the manufacturer before the coating system is applied. Depending on the product and substrate, this may mean ensuring the surface is completely dry.
Repair cracks and damaged areas before applying roof paint
Roof paint should not be regarded as a substitute for repairing significant damage.
Small cracks, splits, gaps and vulnerable areas should be addressed before applying a full waterproofing coating. Depending on the nature of the problem, a suitable roof repair product can provide a quick way of dealing with localised defects.
Promain’s Instant Roof Repair Paint range includes products designed for situations where a fast waterproofing repair is required. Products in the range can be used for problems such as leaking roofs, gutters, cracks and joints, with some products designed for application in damp or wet conditions.
For example, the range includes products such as Acrypol + Waterproof Coating, Rust-Oleum Fillcoat and Britannia Rainshield Emergency Leak Repair, alongside products for sealing and reinforcing vulnerable areas.
These types of products can be particularly useful when an existing leak needs to be dealt with quickly or when a localised repair is required.
However, always check the individual product’s technical information to make sure it is suitable for your roof, substrate and application conditions.
Consider waterproofing the roof before winter
If the roof is in reasonable condition but needs additional protection, applying a suitable roof waterproofing paint can help protect it from rain and other weather conditions.
This can be particularly useful for flat roofs, which can be exposed to prolonged periods of moisture and standing water.
Promain’s range of Flat Roof Waterproofing Paint includes liquid-applied systems designed to provide waterproof protection for suitable roof substrates. Options include products such as AcryPol Waterproof Coating, Rust-Oleum Dacfill and LRS Fastcoat Liquid Roofing.
A liquid-applied roof coating can create a continuous protective layer across the roof, helping to reduce the risk of water penetrating through minor imperfections and vulnerable areas.
The correct system will depend on the existing roof material, its condition and the level of protection required.
Flat roof preparation is particularly important
Flat roofs can be especially vulnerable to winter weather because water may remain on the surface rather than immediately running away.
Before applying flat roof paint, check that:
1. The roof is structurally sound.
2. Drains and outlets are clear.
3. Standing water and drainage problems have been addressed.
4. Loose materials have been removed.
5. Moss and algae have been treated and removed.
6. Cracks, splits and other defects have been repaired.
7. The existing surface is compatible with the proposed coating.
8. The correct flat roof primer is used where required.
Depending on the substrate, a primer may be necessary to achieve good adhesion and ensure the waterproofing system performs as intended. Promain’s flat roof range includes primers and reinforcement products alongside waterproofing coatings.
Apply roof paint in suitable weather conditions
Winter preparation does not necessarily mean waiting until the weather turns cold and wet.
Where possible, plan roof coating work for a suitable period of weather before winter arrives. Always follow the manufacturer’s instructions regarding application temperature, surface condition, drying times and the possibility of rain.
The roof needs sufficient time for the coating to cure properly. Applying a product immediately before heavy rainfall or in conditions outside its specified application range can affect the performance of the coating.
This is also why preventative roof maintenance is preferable to waiting until a serious leak develops during the winter.
Choosing the right roof paint
There is no single roof paint that is suitable for every roof. The best product or system depends on factors including:
- The type of roof
- The existing roofing material
- Whether the roof is flat or pitched
- The condition of the existing surface
- Whether there are existing leaks or cracks
- The amount of standing water
- Whether the coating is for repair or preventative waterproofing
- The expected service life of the system
- Application and weather conditions
For example, a small leaking area may require an instant repair product, while a sound but ageing flat roof may benefit from a more comprehensive waterproofing system.
Promain’s roof coating range covers everything from cleaners, primers and localised repair products through to complete waterproofing systems.
Roof paint or instant roof repair paint – which do you need?
The two approaches serve different purposes.
Instant roof repair paint is primarily suited to dealing with specific leaks, cracks, joints and other localised problems. It can be particularly useful when a leak needs to be addressed quickly.
Roof waterproofing paint is more appropriate when the objective is to protect an existing roof across a larger area and provide a continuous waterproofing layer. This is particularly relevant when preparing a suitable flat roof for prolonged exposure to winter weather.
In some situations, both may form part of the same maintenance project: repair the problem areas first, then apply the appropriate waterproofing system over the prepared roof.
Winter roof preparation checklist
Before winter arrives, work through this simple checklist:
✓ Inspect the roof
Look for cracks, splits, blisters, failed joints, loose materials and signs of water ingress.
✓ Clear the roof
Remove leaves, dirt, moss, algae and other debris.
✓ Check drainage
Make sure gutters, outlets and drainage points are clear and functioning correctly.
✓ Repair damaged areas
Deal with cracks, holes, splits and other localised defects using a suitable repair product.
✓ Check the substrate
Make sure the existing roof surface is suitable for the proposed coating.
✓ Prime where required
Use the correct primer for the substrate and coating system.
✓ Apply the appropriate roof paint
Choose a suitable waterproofing coating based on the roof material and condition.
✓ Allow sufficient curing time
Follow the manufacturer’s application and drying instructions and allow the coating to cure properly before significant rainfall.
Protect your roof before winter arrives
Winter roof maintenance is largely about being proactive. A small defect that is relatively straightforward to repair in good weather can become a much more serious problem after weeks of rain, wind and freezing temperatures.
Cleaning, inspection, localised repairs and the application of a suitable roof paint or waterproofing coating can all form part of an effective roof maintenance programme.
Promain supplies a wide range of roof paints, waterproofing coatings, primers, cleaners and instant repair products for domestic, commercial and industrial applications.
If you are unsure which product or system is suitable for your roof, Promain’s technical team can provide advice on choosing the appropriate coating for your substrate and application.
Prepare your roof now and help keep winter weather outside where it belongs.