Composite Decking Joists

Composite decking joists, pedestals and fixings

Millboard decking has many advantages over natural timber, including that it doesn’t rot, split or warp. Wood’s inherent flaws mean that it is not the ideal material for creating structures to support decks, as for providing the floor surface to the deck itself. That’s why we have developed a range of composite decking joists, bearers, pedestals and fixings that will last as long as our beautiful boards.

Plas-Pro

Plas-Pro is the sub-frame material we have created as the perfect support system for our all-weather flooring. It provides a durable, hardwearing and practical base for Millboard decks and, because¬ it is made from 100% recycled plastic, it can be used even in and around water. This makes it ideal for supporting not just garden decks, but jetties, fishing platforms, roof terraces and boardwalks.

Composite Decking Joists

Plas-Pro posts, bearers and joists can be combined to create sub-frames of every shape and size.

Plas-Pro 50 x 50mm bearers are designed to be used in conjunction with our cradles or pedestals when installed over a solid and stable surface, such as a roof, while Plas-Pro 100 x 100mm posts are for use in conjunction with Plas-Pro 125 x 50mm joists when installation is over a soil or earth base. These composite decking joists can be used with spans of up to 400mm in residential applications, or up to 300mm in commercial and public settings.

Durafix® fittings

Millboard decking can be constructed with screws, just like wood, but without the danger of it splitting. We recommend our Durafix® screws, which can be driven in with no pre-drilling, counter sinking or clip fixings needed. Our decking’s special Lastane® surface will self-heal over Durafix screw heads to provide an instant and very attractive ‘Lost Head’ effect.

Composite Decking Joist Screws

Pedestals and joist cradles

Completing the Millboard sub-frame system are our composite decking joist cradles and pedestals.

Our joist cradles are ideal supports for use in spaces where there is limited height available to accommodate a deck and its sub-structure, especially on roof terraces and patios. They are adjustable to allow joists to be raised off the base by between 10-40mm, allowing water to flow unhindered beneath the joists and so minimalizing debris build-up. The foam pad on the underside of each cradle also offers an acoustic benefit to help reduce sound transfer.

Our adjustable, self-levelling pedestals are ideal for raised decks and terraces, including ones where pipework and services run beneath the surface. Each has a self-levelling head for easier, faster and stable installation. They spread the weight of joists evenly, creating a sturdy support, and are available in five adjustable sizes, providing a height range from 40-210mm. Where more height is required, this can be achieved using our 100mm Extension Collar.

Installation

There is a network of Millboard Approved Installers who are expert in using our decking boards and sub-frame system to create beautiful outdoor spaces. Find the one nearest you here.

Composite Decking Joists

Millboard, high-end wood-free, composite decking. A quick guide for architects

Millboard combines the natural beauty of real timber with the high performance of our unique wood-free material. Millboard is non-porous, which means high resistance to algae growth and excellent anti-slip properties. All of our products, which includes matching profiles and fascias; are scratch and stain resistant, making it a perfect choice for architects when looking for an innovative, beautiful alternative to timber decking.

What does Millboard look like?

Its appearance is the most realistic wood effect decking product in the world! (More importantly perhaps, it looks nothing like plastic). It is an alternative to wood and yet contains no wood or plastic.

What is it made from?

Millboard is made from Polyurethane resin (not plastic) with mineral stone flour commonly referred to as Resin, mineral composite (RMC). It also contains glass fibres to give extra exceptional strength. Other ingredients are high quality colour pigmentation and high-tech ultraviolet light inhibitors for durability and lasting beauty.

What sort of spans should I use between Joists?

400mm centres for residential applications, 300mm centres for commercial and public realm applications. Millboard decking will cantilever over the end of a joist by a maximum of 50mm.

Can you screw fix it like you can with wood?

Yes, it will fix down with screws just like wood will, but without the possibility of splitting. We only Warrant the use of our Millboard ‘Durafix’ screws as these are the only screw that give a satisfactory hidden ‘Lost Head’ effect.

Can you use normal wood working tools?

Absolutely, no specialist wood working equipment is needed, you can even saw it by hand. As with all products that create dust when working with them we recommend, dust bags on saws and dust masks to be used in the control of dust. Gloves should also be worn.

Can the Millboard system be used on a flat roof?

Yes is the easy answer, determine what method of construction has been used for solid wood or concrete slab roofs with a mineral finish. Use our ring supports or joist shoes to position the joists where slope of roof is gentle enough to not be a concern. For a single ply membrane roof use our adjustable self-levelling head pedestal systems to spread the load preventing any point loading, both products will raise the joists above any standing water, prolonging their life while also acting to reduce sound transfer. Both products encourage the free flow of water on the roof membrane.

Will it fade over time?

Millboard has a very high resistance to fading, this is because it contains no wood fibres which typically fade and leave tannins.

Can I butt joint board ends tight to the next decking board?

You can do because the expansion and contraction is minimal, the butt joints should be positioned in conjunction with recommendations contained in the installation guide. A maximum of 2 butt joints before a gap of 2-3mm is desired.

How will saltwater effect Millboard decking?

Millboard is suited to saltwater environments. Salt water will have no known ill effects on Millboard decking and if need be Millboard can live submerged.

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! Millboard is designed as an ultra-low maintenance product and paints and stains will not adhere permanently to the surface of the Millboard in most cases. Clients choose the colour they desire based on the knowledge they won’t have to coat it to keep its colour.

Can you bend it?

Millboard decking boards won’t bend across their width, but curves can be created by using the flexible edging profiles and fascias.

Are Millboard decking products environmentally friendly?

Yes. Because Millboard decking will not splinter, warp or fade in the way wood does, it dramatically reduces the wasteful life cycle of repair and replacement and eliminates the frequent application of environmentally harmful paint, sealers or stains. Millboard decking boards are manufactured with polyurethane resin which can typically last longer than timber, up to 35-40 years (subject to environment). Timber is typically 10-15 years. This avoids unnecessary replacement, which would use up resources on a broader scale. In addition, the manufacturing process of rigid polyurethane resin uses a lot lower energy expenditure (2-6 Mj/Kg) than thermoplastic process (6-29Mj/Kg), thus reducing potential emissions.

Polyurethane has an Ozone Depletion

Rating (ODR) = 0. Global warming

Potential (GWP) = 0.

Unlike wood, Millboard decking is a one-time purchase for most homeowners, with a 25-year Limited residential warranty.

How does the price compare to softwood?

Initially, it is more expensive than softwood decking, but similar in price to a high quality hardwood. What you must remember is that the subframe material and installation are comparable to traditional decking so the labour cost remains similar. Also due to the reduced maintenance requirement, the life cycle cost of Millboard is considerably less than that of softwood decking. It is a much superior quality material to softwood and it is uniform, whereas softwood decking may be warped, contains knots and is inconsistent in density. It’s the perfect alternative decking product.

What material is used for the sub structure?

The cheapest option (applicable to free draining, relatively dry conditions only) is to use treated softwood. The softwood sub structure will obviously decay over time, and may not last as long as Millboard could do. Alternatively we also supply our non-rotting Plas-Pro recycled plastic sub structure system, which is far superior and useful in damp conditions or areas with low air circulation.

Does it become slippery when wet?

Millboard decking has achieved the highest accreditation for anti-slip composite decking in the world! As it is resistant to hosting algae growth and has a textured ‘Lastane’ surface material it is naturally low-slip.

Is there a hidden fixing system?

Yes, the Durafix screws Millboard supplies are made to sink into the surface of the boards and the surface material covers back over leaving only a small, virtually indistinguishable hole

How easy is it to clean?

Once the decking has been installed and after the initial ‘after installation’ clean down there will be very little maintenance required. As the surface is non porous dirt, food and drink spillages do not become absorbed, unlike timber. The simplest way to clean the deck itself if it is really needed is to use soapy water and a brush. It can be cleaned down with a power washer, on low power, if required but this should never really be needed.

View the complete Millboard Collection here or Dowload the Architectural Guide here.