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FAQs Composite Decking


Why choose composite decking?

Unlike traditional timber decking it won’t split, rot or warp and doesn’t require sanding, painting or sealing to preserve it.


Why is composite decking grooved?

Grooved decking surfaces ensures a clean finish without visible screws when the decks are fitted in place.


What is capped composite decking?

Capped composite decking is where the boards are comprised of a wood/plastic core with an added polymer protective shell. The PVC coating prevents mould and mildew attacking the composite.


Which composite decking material is best?

Millboard’s composite decking solutions are widely regarded as market leaders as their polyurethane and mineral stone combined products is one of the most stable materials available. It won’t rot, warp and there is minimal board movement.


How long does composite decking last?

While traditional wooden timber decks have an average lifespan of 10 to 15 years, as composite decking is weather, insect and rot resistant, it can last anywhere between 25 and 30 years, if not longer.


Is composite decking toxic?

Composite decking does not contain toxic chemicals that are often found in pressure treated timber deck solutions.


Is composite decking slippery when wet?

With its textured finishes, composite decking is more slip resistant than wood with smooth spots, which tend to be slippery when wet. Water and ice accumulation can make any deck surface a potential slip hazard though.


Will composite decking burn?

Composite decking is traditionally more fire resistant than its timber equivalent, but it is advisable to check a product’s fire ratings.


Does composite decking fade?

Where natural wood, if left untreated, will eventually fade to grey, composite decking is more fade resistant, but will tend to get lighter in colour tone as time passes.


Can composite decking be used indoors?

Although not commonly used indoors, composite decking is suitable for interior flooring solutions, but would require a solid base.


Can composite decking be put directly on the ground?

As composite decking is highly resistant to rot and insects it is a more suitable choice for ground contact.


Can composite decking be installed over concrete?

Yes, it is possible to install composite deck over a concrete surface, but as with any hard surface, it is best to have a sleeper support system between the two.



FAQs Millboard Decking

Do I need to seal Millboard decking?

No, all Millboard decking is surface-sealed in the factory to ensure they arrive in premium condition. In the first few weeks of use, rainwater will sit on the surface in globules, but don’t worry – this is normal and will stop once the temporary surface seal breaks down.


Does Millboard decking mark?

The Lastane® finish is highly resistant to scratches, food-and-drink stains, and everyday wear and tear. Sharp objects such as unprotected table or chair legs, spiked shoes or metal planter bases can leave marks if dragged across the surface, so take care when moving these items around. The risk of marking from strong dyes and stains such as berries and animal droppings will be reduced if removed as soon as possible.


How do I clean Millboard decking?

Because Millboard decking is made of non-porous composite, it resists mossy build-up and stains, so needs very little maintenance. To remove spills and marks, simply use a mild detergent and a brush. Steer clear of solvents, chemicals and abrasive cleaners that could damage your Millboard decking. There’s normally no need for pressure washing.


Can you recommend an installer?

A nationwide network of Approved Installers are available here. Chosen for their professionalism and high quality, you should always follow normal precautions before entering into a contract with a third party, especially if a deposit payment is required.


Can I use an impact driver?

We advise against using an impact driver to fix the Durafix® screws to the decking as this can break the drive bit and screw head, as well as impede the board from being fixed directly against the subframe.


Are Millboard decking colours consistent?

As with all flooring, we advise buying all the Millboard decking you need at the same time to help ensure that the colour is as consistent as possible. If you don’t order all your Millboard decking at once, you can blend different batches to create only subtle variation throughout your space.


Can Millboard decking be cut just like wood?

Millboard decking can be cut with standard saw blades, although we recommend a carbon-tipped, multi-purpose chop saw. As the formed end of the board is lost when cut, these can be placed in less visual areas against a wall or edging profile. Matching Touch-up Coating for exposed ends is available to buy separately.


What fixings should be used to fix Millboard decking?

Following extensive trials, we recommend and supply Durafix® stainless steel screws, designed specifically for Millboard. There’s no need to pre-drill or countersink Millboard decking, and the unique Lastane® material self-heals, leaving only a virtually indistinguishable mark on the surface.


What if it snows or is icy?

A small amount of granulated white salt can be used to keep your Millboard decking ice-free. Please don’t use rock salt, as this contains clay and grit and can be abrasive. When winter’s over, clean the surface with soapy water and a soft broom.


What sub-frame base system should be used with Millboard decking?

The ideal companion is our all-weather composite decking is Plas-Pro, a durable, hard-wearing and practical sub-frame material for spaces exposed to damp such as jetties, fishing platforms, pools, roof terraces and boardwalks. The Plas-Pro Millboard sub-frame system is made from 100% recycled plastic, which means it won’t rot, split or crack.


Does Millboard decking get hot in the sun?

CAUTION – In high temperatures or prolonged bright sunlight Millboard decking can become hot. Please exercise caution before walking barefoot on to Millboard decking in circumstances where the decking is in high temperatures and exposed to sunlight. In these circumstances, it may be necessary to use footwear. Special caution should be taken when using Millboard decking in areas where there is heat/UV reflective glass.


Does Millboard decking come with a warranty?

Yes. Our warranty gives you peace of mind that we will stand by our word and will hold to the conditions as laid down in the warranty document. We will issue you with either a 25 year Residential Warranty or a 5 year Limited Warranty depending on the installation application of the boards and when it is registered within 90 days of the installation. To register your warranty click here.


Something else?

For any other technical, installation or care questions, go to our contact page, call our technical team on 024 7643 9943, or email us at [email protected]


Order Millboard decking samples

There’s nothing like seeing Millboard decking for yourself. Simply request your FREE sample, https://www.millboard.co.uk/samples/, or go to our store locator to find your nearest merchant or display centre.


Can I use a fire pit / bowl or patio heater on my deck?

In instances where there is burning wood or coal they will need to sit the fire bowl / brazier onto a porcelain or cement tile / slab. The slabbed area needs to extend about 1m outside the fire bowl / brazier. Any embers or burning material needs to be removed immediately to prevent any damage or lasting marks to the Millboard surface. Patio heaters or infra red heaters are not know to affect the Millboard.


What is the different between Timber Joists and Composite Joists?

Timber is the most commonly used sub frame material, and most have a 15 year warranty. However this is only under ideal circumstances and if the cut elements are retreated. In applications where the timber is in contact with the ground or has limited airflow then this will impede on the durability, and in some cases reducing it down to 1/3 or it’s intended lifespan. At Millboard we recommend to use a wood free alternative to maximise the durability of your sub frame system. We have provided the Plas-Pro system, and 100% recycled plastic non-rot profile. When using this as an alternative to timber bear in mind that the structural spans are not equivalent. Please refer to the Plas-Pro brochure or Installation Guide for further details. If in doubt then contact a member of our technical team on [email protected]


Fire Safety

All types of Millboard decking has been tested by BBA, certificate 17/5409 for use as Decking Boards and certification and testing has been to this end.

Millboard decking has been tested to BS EN ISO 13501-1:2007+A1:2009 and has a Bfl-S1 reaction to fire classification (fire test for flooring). Millboard decking is not recommended for use as cladding on buildings 18m (6 storeys) or above, and for other cladding use, it should be subject to Building Regulations to check suitability, use and proximity.

For a full Fire Safety report go to www.millboard.co.uk/help-advice/downloadable-guides/


Can I use a standard board as an edging piece?

Yes you can, where the edge is merely aesthetic, such as a balcony edge, if this is your preferred finishing option. However, where the edge is likely to sustain impact, such as a step, we do not recommend using a standard board. Our edging boards have been specifically designed with high impact in mind and as such have a thicker Lastane® surface to withstand the knocks and scrapes associated with step edges and other associated applications.


My boards have just been laid and have a slight oily / shiny finish?

As the boards are a moulded product we use a release agent in the manufacturing process so when the boards are first delivered this release agent is still on the surface. This may result in the boards looking like they have a shiny or waxed surface or have small particles of dirt and water puddling which could cause slip issues. This release agent will come off the surface within 6-8 weeks due to natural weathering. This process can be accelerated by cleaning the boards with warm soapy water and stiff brush after installation.


What tolerances should be allowed?

There will always be a slight variance in the board’s dimensions due to the fact that we mould from natural oak, and due to the pressure of the foam. Despite this we calibrate the boards to maintain as consistent a profile as possible. The tolerances to allow are: Width: ± 3mm. Length: ± 5mm. Thickness: ± 2mm The dimensions of the Weathered Oak style may vary more between moulds due to the fact that they are moulded from timeworn oak with minimal changes to the dimensions.


Can you use it for load bearing applications (i.e. structural)?

It is not recommended to use Millboard in structural applications. Millboard decking would need to be fixed to a structural frame, either made of timber or ‘Plas-pro’ recycled plastic.


Can you paint/stain it?

No, it is not needed! Durable, through-body coloured and UV stable, Millboard is a low maintenance product that does not require a protective coating. Paints and stains will not properly adhere to the surface.


Are Millboard Decking board sizes exact?

The majority of our boards are manufactured to the sizes stated on our product pages. However, on occasion some of our board sizes can have a nominal difference and can be manufactured to 30mm or 31mm. The boards that are sometimes this smaller size are still within tolerance.

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