How Much Cladding Do I Need And How Much Should It Cost?
Getting The Boards Down
When you’ve started a time-consuming project like cladding a house, a number of technical criteria might come to mind, depending on your preferred build or your interest in wood. However, we at Logie Timber find that, regardless of the customer’s experience or build, one question stands above all others – how much will this cost me?
This question is entirely reasonable. Everyone’s got a different budget, and nobody goes out into the wide market of timber actively looking to get ripped off. However, the mere cost of wood itself isn’t the only thing you should to look at when it comes to cladding a house. There are all sorts of additional costs that are an integral part of setting up your house’s cladding properly, safely, and legally. Let’s look at some factors that might affect the cost of your house’s cladding.
The Wood Itself
Different timber species can vary wildly in price, for a whole host of reasons. But, more than that, the same amount of the same wood can vary considerably in price between different sawmills or providers.
At Logie Timber, for instance, our timber may cost more than others on the market. That’s because we source our wood locally and sustainably; we dry it out for as long as it needs; and we cut down right to the heartwood, giving you only the strongest and highest-quality wood, without including a lot of sapwood that might pad out other orders.
Each sawmill will work out the cost of its timber differently. The eternal question of ‘what wood should I use’ also has several factors connected to it, such as personal aesthetic preference; resistance to rot, decay, fungi or damp; acceptance of different treatments; or even just availability in your area. (We can, however, help you narrow this down a little, if durability to the great outdoors is your main concern (link to ‘What wood to use outside’ article). Ultimately, though, it’s up to you to decide what timber you’d like.
For our example today, let’s assume you’ve chosen to buy Douglas fir – a sturdy, dependable, and hard-wearing wood – from us.
The price can differ based on the style, but let’s say you’ve chosen to buy Douglas fir cladding cut to a horizontal shiplap style (pictured above). For Douglas fir wood cut into 140×22 mm boards, we charge £4.06+VAT per metre, which translates to £31.26 per m2.
Cladding larger buildings will cost more, and that cost can scale up rapidly. Make sure you measure out the exact length of your property’s walls ahead of time before you look into cladding, to have precise figures you can compare to the cost of the timber itself and make sure everything’s still within your budget.
Figuring Things Out
When you’re calculating the cost of cladding a particular wall, you should start with the square meterage of the wall itself. Measure the wall’s length and width, and multiply them together.
So, for example, a wall of a shed that’s 2.5m wide and 2 m tall would have a square metreage of 5m2 (2 x 2.5 = 5). Once you have that number, it’s then a good idea to work out the profile you want to use. We’ll discuss profiles below, but your choice of profile might well be the result of any number of factors, such as stability, weather resistance, cost, or aesthetic preferences.
Cover & Profile
Different profiles will cover different amounts of the surface they’re applied to. The area they cover is listed in the profile as ‘cover’, and it will often be less than the actual length of the board, owing to intentional gaps left in the design. Using the profile of the shiplap style, you can see that it has a cover of 130mm, despite the boards being 140mm long. This is because of the intentional gap left at one end of the board, such that the lower board can be slotted in beneath, to aid in stability and ventilation.
Board Calculation
Once you’ve calculated the size of the wall, you need to work out how many linear boards there are in a square metre, and thus how much each square metre of the project will cost you. To do this, take the cover of a board from the profile you’ve chosen, and divide 1000 by that number. (Again, using the shiplap example, 1000/130 = 7.69LM per m2.) You can then multiply the regular cost by that value.
So, let’s use that simple shed example again. If you were using shiplap style on that shed, you’d need five square metres worth of linear metres per wall. If you were using Douglas fir cladding, which in that style costs £4.06 per m2, you would multiply 7.69 x 4.06, giving you a result of £31.22 per m2.
Mark For Flow
When measuring, bear in mind that you’ll need to leave an 8-15mm gap between boards to get sufficient ventilation between and behind the cladding. When you’re designing your cladding (or choosing from a catalogue), simply figure out how much of a gap you want and subtract that number multiplied by the number of boards. (For instance, if it was going to take fifty boards to clad one side of the house, and you wanted a 12mm gap between each board, you would subtract 600mm (50×12) from the actual length of the wall itself.) You also need to leave a 200mm gap between the bottom of the cladding and the ground, to prevent excessive moisture, so factor that in as well.
Battens
Battens are thin, narrow boards that cladding boards are usually fixed onto, creating a space between the house’s walls and the cladding . This helps create a cavity – a necessary part of aiding ventilation and preventing rot. If you’re fitting your cladding horizontally, you want vertical battens. If you’re fitting it vertically, you install it onto horizontal battens.
Because battens arranged horizontally can obstruct ventilation (as they stop air flow by being flush with the house), they’re often separated from the walls by ‘counter’ battens, which are vertical battens placed underneath the horizontal ones. (You can avoid needing counter battens by having a board-on-board closed-joint style of cladding, which allows ventilation and drainage due to its staggered design; however, this is relatively uncommon.)
When buying your cladding, the battens will be sold separately. Given that they won’t be on display, you won’t need to worry about their look or the treatment used on them so much, but make sure the wood itself is of a good enough quality to keep your cladding holding strong.
Other Cladding Factors
When buying your cladding, you also need to bear some other factors in mind, depending upon your build. Some other purchases you might need for your cladding include insect mesh, cavity barriers, insulation, sheathing, and treatment. You’ll also definitely need screws – we recommend Rothoblass screws for the cladding we sell, but other options are available. Just make sure you use stainless steel screws, not galvanized ones.
Insect Mesh
Insect mesh is often used as a means of keeping out small insects and mammals, which may or may not be necessary depending on your building’s age and location. Cavity barriers are additional pieces of fire-retardant material, inserted behind the cladding, to prevent fire spreading as easily between the different sections of the cladding. These are especially important if your design involves fitting cladding around windows. However, if the building you’re fitting cladding to is a more modern design and is fire-proofed to a good standard, you might not need them at all.
Insulation
If your project is in a colder part of the world, you might want to put insulation under your cladding, to prevent frost-related issues and build-up of moisture behind the cladding, as well as helping the energy efficiency of the building. Likewise, sheathing can help protect your cladding from strong winds.
Treatment
Treatment can reference two different factors – whether wood is treated or not as part of a factory process, or whether it’s treated by yourself with a product like an oil, coating or staining. Whether you even need treated timber or not is a matter we’ve already covered (link to ‘Do I Need Treated Timber’ article), but if you decide on getting treated timber, you need to make sure your screws and fixtures are made of the right material (usually stainless/non-galvanized steel).
Cladding Questions
While there are a wide number of factors that can complicate your construction efforts, remember that there are a number of resources available online that can help you figure out the cladding you need, from size and cover to type and treatment. These range from step-by-step illustrated guides, to full YouTube tutorials.
For our part, we at Logie Timber are more than happy to help you navigate this process. Feel free to talk to our team of experts any time; either by reaching out to us on social media (on Facebook or Instagram), call us on 01309 611769, or send us an e-mail at info@logietimber.co.uk.
