What does GRP mean?

Glass(fiber) Reinforced Plastic (GRP) is a composite material that consists of a polymer matrix and glass fibers. The polymer matrix is usually an epoxy, vinylester, or polyester thermosetting resin.

Fiberglass sheets are a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet, or woven into a fabric before being used with a resin/epoxy which hardens. Which results in a strong lightweight product.

It’s for this reason GRP is widely used and most commonly used in the marine industry as well as the roofing industry.

What is GRP Roofing?

GRP Roofing systems combine a few different materials. This includes the OSB3 decking, the Fiberglass material, resin/epoxy, and the durable topcoat. This mixture of materials when laid correctly creates a strong and robust roofing material. Usually fibreglass preformed trims are added to create a roof directs rainwater to the designed drip edge/gutter.

Fibreglass roofing consists of wetting out layers of fiberglass mat on the roof of the building. When cured, your roof should have strength and provide a continuous waterproof barrier across the whole surface of the roof.

So lets start from the beginning. You have your roof structure with bare ceiling joists, which you would usually attach a quality OSB3 decking (Usually min. 18mm thick) with insulation to help reduce heat loss and create a warm roof. You can install without insulation making a cold roof but do take into account the Part L of Regulations.

GRP edge trims are then fitted to finish the sides, making sure water can then run to the drip edge. GRP Laminate which is made up of the fibreglass material and your resin which you will need to mix yourself can then be laid. Usually a 450 csm (chop strand mat) is the usual for flat roofs that won’t have people walking on it, if it’s going ot be a terrace then you will need a thicker mat, something like a 600 csm. Once this is all laid, the roof can then be finished with a topcoat. Most suppliers will offer a few different colour choices, usually a dark grey is the standard and most popular topcoat colour but this is persoanl choice as you may want to match it to your windows, doors or skylight. The topcoat then finishes your roof perfectly and your will now have a roof that is extremely strong as well as watertight. Most GRP systems come with a warranty if installed to the correct guidelines or by a specially qualified installer.

So, benefits of GRP Roofing:

  • Easy installation
  • Superior durability/long life
  • No joins or seams like felt
  • Flame-free and safe installation
  • Easy repairs if needed
  • Great finish and aesthetics – Range of colour finishes
  • Can be used with virtually all Flat Roof Windows

GRP Roof

The post Waterproofing Explained: What is GRP Roofing? appeared first on The Skylight Company.


By: admin
Title: Waterproofing Explained: What is GRP Roofing?
Sourced From: www.theskylightcompany.co.uk/waterproofing-explained-what-is-grp-roofing/
Published Date: Fri, 22 Jan 2021 12:38:37 +0000

Frequently Asked Questions

Skylights let in more light that windows?

Skylights, due to their location, can let in more sunlight than windows. Skylights allow for more natural light to be reflected from the sky, and directed into the living areas below. Because they are placed at an angle, skylights can shed more sunlight than traditional windows on any given day. This often results in brighter rooms that have a higher atmosphere.

Skylights also have unique features that let you bring in light even in the darkest hours. By allowing natural daylight to pass through the roof, skylights help create a warm and inviting indoor space for year-round comfort, especially in climates where sunlight is limited during certain months of the year.

Modern window designs come with innovative technologies that enable them to capture the same amount of daylight offered by a skylight while maintaining a high level of privacy and protection when closed. But, in most cases, multiple traditional windows will not provide the same level or illumination as a skylight.

When considering different options for bringing the daylight into your home or office, weigh up your needs and preferences before making a decision as both solutions offer their own unique benefits.

What is a common problem with skylights?

Skylights offer natural light and can cause some problems.

Moisture is a major issue, as moist air can easily pass through the skylight and condense on the cold glass and frame, leading to mold or rot. A failure to seal the window can lead to air leakage that will increase energy costs.

Also, improper installation can lead to problems. An insufficiently sealed skylight may not offer adequate insulation against extreme temperature. This could cause an increase in your heating bills during winter, or excessive heat in the summer.

Skylights can also have uneven glazing. This is when the glass doesn’t fit into the opening properly or sealant fails to protect the edges. If this happens, it can lead to water infiltration as well as problems with moisture control.

Finally, improper ventilation may be an issue as well as dust accumulation from inadequate air circulation from outside into your home; it’s important to ensure ventilation fans are included for the best protection against dirt buildup and sweltering temperatures in summer months.

Are skylights more affordable than windows?

Skylights can be less expensive than windows. This is due to the fact that they are smaller, easier to install, and provide direct lighting with no additional energy costs. The type of window or skylight you choose can drastically affect the project’s overall cost, so it’s important to consider your options carefully.

Skylights can be made in any shape, but typically they are either rectangular or square panels. They range in price depending on their size and materials (such as glass and framing). Skylights are often framed with aluminum or wood and may be insulated for better heat retention.

Windows are available in many different sizes, types, materials, and glazing options. All of these factors affect the installation cost. Windows require a more complex installation because of the custom sizing required to ensure they fit within existing structures. Windows are also more expensive than skylights, as they require several frames to insulate the space.

So when it comes down to budgeting for an interior installation project such as window replacement or new sky-lighting additions, skylights will often come out as being cheaper than windows due to their simpler design and installation process.


  • Similarly, those who select VELUX solar-powered products will enjoy the added benefit of qualifying for a 26% tax credit on their purchase. (skylightsforless.com)
  • If you replace your water heater the following year, you would be eligible for another 30% tax credit, up to $2,000 plus up to $600 if you need an electric panel upgrade to accommodate the new water heater. (energystar.gov)
  • The flat roof skylight can help reduce this noise by up to 50%, making it much easier to relax when inside your home. (roofing4us.com)
  • However, including all the expenses, skylight installations can cost you a good 600$ to 2500$. You can choose the skylight particulars according to your project specifications and budget constraints. (glassgenius.com)
  • Skylights let 30% more natural light in as compared to conventional wall windows. (glassgenius.com)

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How To

How to Select the Best Skylight For Your Home

It is important to choose the right skylights for your home. It will impact both the aesthetic and functional aspects of your space. You should consider the size, location, type, and number of skylights.

You should consider the architectural design and style of your home when selecting a rooflight. It’s important that you select a style or shape that complements your interior design and roofline. Dome-shaped rooflights are more common for new constructions as they provide greater coverage than either rectangular or square-shaped options. If you’re looking to add a unique touch to an older home, consider octagon-shaped units or special designs like half moons or pentagons.

Measure the area where the skylight will be installed on your roof before you decide how big it should be. The standard sizes vary depending on how much light is desired. They can be 20″x34″ or 52″x90″. So choose the size that suits your needs.

When choosing a skylight for your home, consider the material you use. Vinyl is light and easy to install. Glass is more expensive, but it is more resistant to temperature fluctuations and humidity changes. Be aware of the environment and what it is like to snow, before you decide on the right material.

Make sure to investigate the various types of lighting systems and shades that are available to match your skylight. These options can reduce heat gain or loss due to outside weather patterns, while also providing privacy. These aspects will help you choose the right skylight for your space.

Did you miss our previous article…