Monday, 26 January 2015

How to tongue and groove...

Before I start, let me remind you that I'm not a master carpenter. I know my stuff when it comes to paint but with carpentry I just fly by the seat of my pants.
Having said that, I've successfully completed four tongue and groove projects now and I've learnt many a thing along the way which I'd like to share.

Tongue and groove is cheap and adds period charm. It's very simple to do but there are a few rules you need to be aware of.

Here are my DO's and DON'TS...

DO acclimatise your wood by unwrapping it and leaving it FLAT in the room you're going to use it in.  The temperature and humidity of the wood must match that of the room it'll be used in to avoid shrinking, expansion and twisting. Leave it for a few weeks.

If nailing, say to clad a door like I did, DO transfer the line of the batten you're nailing into to the topside  of your T&G so you know where to nail. You can erase pencil lines later.

If you're cladding a wall, you DON'T need to attach battens to the wall first. Modern adhesives that are suitable to stick skirting boards up will be fine. However DO seal the wall first if it's bare plaster. Those glues don't work well on unsealed plaster as it affects the adhesion. (You can seal a wall with diluted PVA glue.)

You might consider using a batten though if you're cladding the inside of an exterior wall as the gap you create between wall and timber can be filled with insulation.

DON'T be tempted to whack it in with a hammer if it doesn't go in easily. You'll damage the edge so that the next piece won't fit either. Instead use a block of wood as a buffer between your hammer and the fragile groove and tap gently if you have to. 

DO work your way out of a corner making sure that the groove faces the right way so you'll be able to get that last piece in. A bit of forward planning will prevent much gnashing of teeth and tearing of hair later.

DO work out where the joins in your work will be my measuring and marking your way out from the centre or one side. You don't want to be left with a 1cm bit of T&G on an edge. Figure it out before you begin.

DO dry fit your pieces to make sure it all fits as you expected it to.

DO use a spirit level!

 DO run a bead of glue down each groove before you slide the tongue into it. Wipe off any excess immediately with a damp cloth.

The piece of T&G in the picture below was not wood glued or held in place with adhesive on the wall.  It was so fiddly to get in that I just left it, held in place by the surrounding pieces...

 You can see how the wood has shifted and the caulk and paint have cracked. I'm going to have to fix this. It's not so bad if it's just one piece. If it was the whole wall I'd weep. DON'T let this happen to you. Use adhesive on the wall and wood glue down the joints.

To caulk or not to caulk?

If you want to paint your tongue and groove and you've glued it down the grooves and glued it in place, you DO need to caulk in every joint so that the paint doesn't crack. Caulking won't ruin the look. You're not obliterating the groove, just filling the very bottom of the crack. Caulk is a flexible filler so there's a degree of movement which prevents cracking.

If you haven't glued everything together, DON'T caulk as your t&g will have more movement. Try not to get too much paint in the crack where the joins are. Then your boards can move without cracking the paintwork. 

If you're painting, DO treat your knots with a knot blocking primer suitable for the type of paint you'll be applying over the top. You can fill knot holes if you want. I don't usually bother as there's something honest about them. If you want knot free perfection perhaps MDF panelling might be more suitable. 

Caulk a thin line right the way down every join. Smooth it into the crack with your finger and wipe away the excess with a wet cloth.

If you're not painting, perhaps just varnishing or white washing, finish the face of your boards BEFORE you fix them. 

For BATHROOMS or high moisture areas you'd also need to prime/paint varnish the BACK of the timber. This will help seal the wood, protecting it from expansion and contraction with the increased humidity.   DO finish the front of the boards BEFORE you fix them, not forgetting wood glue down every groove as this will also prevent movement. I wouldn't caulk or paint over the joins. If any movement does occur your joints won't be cracking your paint finish.

I hope that helps if you're thinking of planning a tongue and groove project. It really is an enjoyable thing to do with a little forward planning.

As for last weeks post, well aren't you all a bunch of smarty pants? My unsavoury sounding fleamarket curiosity...

was of course an ink pad....

...albeit very much dried up and completely useless now. I can't believe how many of you got that right. I was clueless despite my O level French.

It's nice to know that my blog has such an educated and intelligent readership.

The winner is Teri. Please send me a message Teri with your address and I shall pop a surprise in the post to you.

I'm still grappling with the bloody corner cabinet and wishing I'd left it in the skip. Meh. Back soon...


  1. Merde! I was off the mark despite having one-to-one French tuition for a year now.... funny how there's no mention of encre. Great T&G tips but I don't think I'd have the patience and would sling up that MDF stuff if I had to.
    Show us your corner cabinet post grappling please. xx

  2. ooh me! ooh happy dance. My skip rescued screen is still leaning on the wall in it's whiteness, begging for a 3rd coat, and maybe a 4th before it gets a treatment! Looking for email button now ...

  3. Heavens Em, is there anything you can't tackle.....I'll pass on your tips to the handyMAN in the house xxxx

  4. I was so close and yet so far with my guess.

    Lizzie Dripping

  5. Great tips :-) Ahh well I got it wrong think I said soap lol ;-) I was never good at French. Good luck with restoring the corner cabinet, dee xx

  6. You have inspired me to crack on with my (tongue and groove) bathroom, I've done all the difficult stuff and it's ready for it's final coat, I'd just ground to a halt - post of finished room soon (ish) promise!

  7. Well, it's a bit late for me to glue all my joins on my beadboard. I've got half of it up and didn't do any gluing and the other half is dry fit, waiting to be adhered to the wall. I've used this product before on the backs of cupboards, so I didn't bother with glue or caulk, but now you've got me scared of how it's going to look on my kitchen walls! I really didn't want to caulk the joins, but now I'm going to rethink that before I paint the whole works. Thanks for the tips, Emma!

  8. You're so clever!

    Re your corner cabinet - do not despair, just pause and reflect. I bet it turns out good in the end. I started my kitchen table before Christmas, sanding, more sanding (all by hand), sanding after Christmas with electric sander, wash of paint (looked good) waxed it....oh dear, looks a bit pink.....sanded again, waxed again with tinted wax, still not right.....oh dear oh dear. "I hate it! I wish I'd never started it! Why didn't I just put up with the orange pine!!!!" More sanding (partial, by hand). Waxed again. Ahhhhhhhh, finally, looks good! And the Little Green Citrine on the legs is bang on!!!! And I've had compliments! So stick at your corner cabinet!!!! Can't wait to see the results!

  9. You ARE clever, EK! I'm a DIY disaster, so it's probably as well I don't try my hand at T&G...
    But I still maintain my answer about the tin was correct. Just saying. xxx

  10. 2 Questions! Can you gloss-paint over pre-varnished (old) T&G? Or does it need an under-coat? Also, what about chalk paint on a new bare-wood T&G ceiling? Is that recommended?

    1. Yes, but you don't want to use oil based gloss if you're painting it white as it will turn yellow in a few months. You will need to use a stain stopper like Blackfriars problem solving Primer on every knot. Twice. And a primer to help the paint stick. I'd try a water based gloss or eggshell. Use primer to get it white first as it's more opaque than paint and cheaper.

      Chalk paint on a bare wood ceiling ONLY if you use a stain stopper like Blackfriars on the knots. Twice. And using a cheap primer (like Wilkos) will mean you use less chalk paint which is more pricey. But seeing as ceilings are generally white, chalk paint might be an expensive way to go. It's also very brush strokey and rough looking. I wouldn't. But I'm NOT a chalk paint fan.


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