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What Material Should I Use for My Rooftop Decking?

When it comes to building a rooftop deck, the correct choice of material is important. The material for any roof decking should be durable and long-lasting. To help you, we have drafted this article to help you make the best-informed choice.

Roof Decking Materials

There are different types of materials that you can use to build decking on your rooftop. You can use the same decking material as you would on a ground level deck. Examples of outdoor flooring materials are wood, timber, aluminium, PVC and composite decking. These types of outdoor flooring are the most common decking materials available on the market.

If you are building rooftop deck then you must look at local building regulations, as even though you may be able to use similar materials as a ground level deck, they may need to be fire rated. Composite decking upon request, normally, you can purchase composite boards with different fire rates, as the formula used will have to be altered to achieve a fire rating, so do check first before installation and purchase.

If you do require fire rated composite material or boards these can be purchased in non fire rated, fire rated E to B. Fire rated A is non- combustible materials and examples of materials you would need for Fire rated A are aluminium, fibre cement or porcelain. Composite decking materials sold in the U.K. doesn’t achieve fire rated A at present. So do check before your construction if you require any fire rated products for your roof top deck.

1 Composite Decking

Composite is regarded as the best flooring material to use when building a decking area. In the main due to its durability and long service life. Notwithstanding its strength, high resistant to water and wood eating insects making it superior to timber and PVC decking.

Capped or shielded composite decking offers additional protection from the sun’s harmful UV rays helping to further minimise colour fade*.

Additionally, composite decking will not require painting or staining like wood. In addition to its durable long-lasting benefits, homeowners also value composite decking for its beauty and aesthetics.

These features as mentioned make it one of the best flooring materials for any outdoor project, when building on a roof top deck low maintenance and resistance to moisture, stains and UV rays make it an ideally choice when build a roof top deck, but like stated above ensure you check building regulations and remember composite decking can achieve a fire rated B, but this is a commercial or tailed product for most suppliers, so this may not be readily available and can take longer to arrive than normal.

2 Wood and Timber Decking

Timber decking is a traditional decking material you can install on the ground or rooftop of your home. You can use either treated wood, cedar, redwood or IPE for wood decking. Timber decking is generally a cheaper option with less value compared to composite decking boards.

In terms of aesthetics, wood fades on exposure to UV rays. To maintain the look of timber, you will need to annually apply stains or paint it to protect it from the elements and keep it looking good for longer.

Wood decking can warp, break or splinter over years of use. Wood decking will absorb water and moisture and swell when humidity is high, leading to possible splintering, cracking and even failure. Furthermore, wood decking is also susceptible to insect damage and maintaining wood decking is timely and costly.

Wood decking shouldn’t be your first-choice material for a rooftop deck, the high maintenance, short life, high risk on rot, slip, decay and high fire risk makes this the less favourable product for fitters and homeowners, unless you are on a tight budget.


3 Plastic Decking

Plastic or PVC decking contains 100% plastic, making it a waterproof decking material, but also the most expensive type of decking material you can use for ground and rooftop decking. Similar to composite decking, plastic is also resistant to rot. It is durable and will not warp, crack or splinter like wood. PVC decking has similar features to composite decking, but the latter has a longer lifespan than the former.

PVC is a good decking material you can use for rooftop decking. Using plastic offers increase water resistance and also easier to maintain, like composite decking. You do not have to worry about applying paint or stain, seal or sand to the surface of your PVC decking. The new editions of PVC decking normally have an ASA surface layer that offer excellent stain and scratch resistance, along with a unique wood grain capturing some of the natural aesthetic to wood.

PVC decking is a favourable choice for a rooftop, its a low maintenance decking solution in which wont rot and offers excellent scratch and stain resistance. The only drawback for PVC is it can weaken in high temperatures and isn’t a eco friendly product when compared to other options.

4 Aluminium Decking

Aluminium decking reaches our options for a roof deck why? aluminium decking offers great corrosion, scratch and UV resistance. Its durability and longevity simply cant be rivalled against any other decking option in the market today. What gives aluminium decking an edge against the other options is its fire rating, aluminium decking can achieve fire rated A and this maybe a spec in which you require, if not it gives you the piece of mind that your material choose offers supreme fire protect and future proof you flat or home against any changes to building regulation for roof top materials.

The only draw back to aluminium is its high cost, costing on average £144 per sqm, also not that if installed with timber joist pressure treated timber should be avoid to eliminate any damage.



A rooftop decking material should be durable and easy to maintain with an extended lifespan. Compared to wood and PVC, composite decking is your best option, but if cost isn’t an option, we would personally go for aluminium decking due to its protect against fire and future proofing your roof top against any changes to building regulations.

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