Types of Metal Roof Sealants

To maintain the condition and durability of your metal roof, it is important to understand the different types of sealant.

• Acrylic & Latex 

These water based sealants are non-flammable, have no strong odour and offer UV protection. However, both acrylic and latex sealants evaporate as they cure, which can lead to shrinking and cracking.

• Polymer

Polymer sealants are designed to be extremely durable against harsh weather conditions. They typically release fewer VOCs and can be easily colour matched.

• Silicone

Silicone sealants are both water and UV resistant. They adhere well to metal surfaces and maintain a degree of flexibility that enables them to withstand fluctuations in temperature.

Factors to Consider When Choosing a Metal Roof Sealant

Benefits of Using a Metal Roof Sealant

By using a metal roof sealant to seal your roof, you will be protecting the roof’s material and the structures below, which could be subjected to water damage and pest infestation if not properly sealed.

Here are some of the main benefits of using a metal roof sealant:

• Increases the lifespan and longevity of the roof

• Waterproofing the seals keeps water out of your loft and walls, preventing costly water damage.

• Protects the roof panels from corrosion

• Improves energy efficiency by creating a protective barrier from environmental factors, resulting in better insulation for your home.

• Improves the aesthetic appeal as sealants come in a variety of colours enabling you to customise the appearance of your roof.

How to Apply Metal Roof Sealant Correctly

Before you begin sealing your metal roof, it is important to make sure your roof is in optimal condition to obtain the best possible finish.

Preparation

Cleaning the roof

• Thoroughly clean the exposed surfaces of the roof and surrounding areas to remove dirt, leaves, and organic matter. 

Depending on what equipment you have to hand, you can either scrub the roof surfaces with a mild detergent or use a pressure washer if available. 

Once the surfaces have been sufficiently cleaned, rinse to remove any soap residue and allow to dry fully for 24 hours.

Repair any damage

Once the roof has been cleaned, inspect the roof’s surface for any damage.

These are some possible signs to look for:

• Holes in the panels from fallen branches, stones or hailstorms
• Rust patches on the roof panels or flashings
• Any missing flashings
• Loose panels
• Blocked gutters
• Broken shingles

Make sure to repair any of these issues before sealing the metal roof. For severe roof damage, ensure to contact a professional to carry out the repairs.

Make sure the roof is dry

You should schedule the project on a warm and sunny day as the roof needs to be fully dry before sealant is applied, as otherwise it may not adhere properly and could fail. It is important that after cleaning the roof, it is left to dry fully.

Applying Metal Roof Sealant

The process to apply roof sealant involves spreading a layer of sealant across the exposed areas of the metal roof, sealing both the edges and the fixings.

It is important that before dispensing the product onto your metal roof, you read the manufacturer’s guidelines and the technical data sheet listed. 

Essential Tools Needed:

• Pressure washer / brush for cleaning the roof
• Waterproofing Roof Sealant 
• Sealant Gun
• Roof & Gutter Sealant
• Paintbrushes
• Paint Roller
• Safety Gloves

If working at heights, you may want to use a safety harness and for working on the roof surface it’d be advisable to invest in some non-slip shoes.

The Main Surface of the Roof

• You should apply the sealant using either a paintbrush or a roller brush, working from the top downwards. 

Make sure to work in small, vertical sections, applying a single layer at the time, so that the sealant is applied evenly.

• While applying, make sure to keep an eye out for any missed patches or drip marks. Once fully applied, if any areas have been missed or are uneven, you may want to go back over them.

Seams and Flashings

• Once the main surfaces of the roof have been sealed, you will want to take a smaller, more intricate brush to apply sealant to any exposed flashings, fixings or areas that are hard to reach with the roller brush.

At this stage you can also apply a cartridge sealant, to any joints, seams or overlaps in the roof panels. It is easy for water to get in between these surfaces, so make sure the sealant securely fills every gap.

Curing Process

Make sure to follow the guidelines issued by the product manufacturer, but typically you should let the metal roof sealant cure for between 24-48 hours. When planning to seal your metal roof it is important that you try and schedule it during a period of dry weather. 

Maintenance Tips for Metal Roof Sealants

You should expect to replace roof sealant every few years however, some sealants can last up to 20 years with the right maintenance and care.

Here are some ways you can protect and maintain the condition of your roof sealant:

• Regularly check for leaks inside and on the roof
• Clear away any debris and dirt, do not allow for it to build up
• Book in for an annual roof inspection each year
• Routinely clean out your gutters to reduce the chance of pooling water
• Maintain a high quality roof coating
• Touch up the roof sealant when you detect signs of wear and tear and reapply when needed

Metal Roof Sealant Safety Precautions

Working on a metal roof can be slippery, and can put you at risk from injury. Below are some key factors to consider before attempting to go up onto your roof and before applying the sealant:

• Wear non-slip rubber soled shoes to make sure you have sufficient grip when walking on the roof.

• When working at heights, you should wear a harness with a safety rope attached, so that you can move freely around the roof without risk of injury.

• When dealing with a chemical substance such as roof sealant, it is important that the product does not get onto your skin, so it would be advisable for you to invest in safety gloves, and eye protection.

Frequently Asked Questions about Metal Roof Sealants

Why is sealing a metal roof important?

Sealing a metal roof is crucial in preserving the condition of your roof and prolonging its lifespan. Using a roof sealant will not only prevent water damage and infiltration, but will make the surface of your metal roof more corrosion and weather resistant. By applying a roof sealant, you can significantly increase the structural integrity of your metal roof and increase your energy efficiency.

Can I seal a metal roof in cold weather?

You can seal a metal roof in moderately cool environments, however it is not advised to apply sealants in temperatures below freezing. It is more important that the conditions are dry. Sealants should be stored in temperatures between 5℃ to 25 ℃, so it is best to store them indoors.

Can I paint my metal roof after sealing it?

It is important to make sure that the paint you are planning on using is compatible with the sealant. If compatible, once the sealant has fully cured and dried, the surface will be paintable.