ᐅ Installing Tongue-and-Groove Boards in the Attic – Tips

Created on: 15 Oct 2023 15:50
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Bau-beendet
So, I need to start addressing this topic. The tongue-and-groove boards have been stored in the attic since the shell was completed. I am currently considering how to approach this properly.

The initial plan was to install the tongue-and-groove boards from gable to gable, laid perpendicular to the (purlin?) beams of the roof structure (which you essentially walk on, going from eaves to eaves). However, this would mean the tongue-and-groove boards would be directly on top of the insulation placed between the beams, which raises concerns regarding air circulation.

A while ago, I received advice to raise the boards. Now, to avoid adding multiple (unnecessary) layers and increasing the height too much, I am thinking of installing battens lengthwise from gable to gable instead of laying the tongue-and-groove boards lengthwise. What spacing should I use between the battens? Then, the tongue-and-groove boards would be rotated and laid on the battens, this time running from eaves to eaves.

Since the boards will need to be cut on site, is it a problem if the cuttings—mainly fine dust from cutting—fall onto the insulation? How can this be prevented?

Thanks for your feedback!
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xMisterDx
17 Oct 2023 22:26
Isn't at least 5cm (2 inches) recommended for proper ventilation behind the cladding?
Tolentino17 Oct 2023 22:29
With 4x6 cross battens (vertical), he does have them. I know of 4.
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Bau-beendet
17 Oct 2023 22:47
In that case, I would only have a 2cm (1 inch) edge if the tongue and groove boards fit tightly edge to edge.
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xMisterDx
17 Oct 2023 23:27
The battens have the advantage of being incredibly cheap. A 40x60mm (1.6x2.4 inch) batten costs only 1.69 EUR/m (0.51 USD/ft) even at premium retailers.

It also depends on the spacing of your collar beams, right? Mine are 890mm (35 inches) apart, and even 23mm (0.9 inch) thick wood bends quite noticeably under its own light weight.

Going up to 28mm (1.1 inch) or thicker quickly makes things ridiculously expensive...

So I’ll stick to your original plan: nail battens onto the collar beams and then add another layer of battens perpendicular to them, spaced about 40-50cm (16-20 inches) apart. You can stagger them at the joints, which solves the problem of the small bearing surface. On top of that, I’ll install 23mm (0.9 inch) tongue-and-groove boards, which are also reasonably priced.

To really feel comfortable with a bearing distance of 890mm (35 inches), I’d probably need something like 35mm (1.4 inch) thick boards... that might be okay for a terrace, but not for a storage room for junk and odds and ends :p
Tolentino18 Oct 2023 00:11
That's why I wrote cross battens with a spacing of 60cm (24 inches). The 4cm (1.5 inches) thickness is sufficient. If in doubt, pre-drill holes through the floorboards to prevent any splitting.
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xMisterDx
18 Oct 2023 00:17
Isn't it possible to just nail everything?