Accoya for a front door

[RobinBHM]

I've always put the radius on joinery, but what does the V achieve, please? I appreciate it probably looks neat, but presumably it serves a purpose

but a V still exposes a thin joint line (in the middle) where the paint finish will crack first and where capillary action can allow water to be drawn into the joint

Strictly speaking, both stile and rail shoulder should have a 3mm radius which forms a V when assembled.

The reason is that timber shinks almost nothing in its length but significantly acrosscits width. So the bottom rail of a door will expand and contract, fracturing the paintlne. The paint film at the joint, if you think about it as 2 separate pieces, just stops square.

With a radius, the V jount that is formed can have some flexible V joint filler in it. Then the door is painted. In service any expansion moves the filler but the paint remains intact.

Look at almost any old painted door, most will have a fracture line at the joints.

 

[Woody2Shoes]

I've always put the radius on joinery, but what does the V achieve, please? I appreciate it probably looks neat, but presumably it serves a purpose

but a V still exposes a thin joint line (in the middle) where the paint finish will crack first and where capillary action can allow water to be drawn into the joint

Strictly speaking, both stile and rail shoulder should have a 3mm radius which forms a V when assembled.

The reason is that timber shinks almost nothing in its length but significantly acrosscits width. So the bottom rail of a door will expand and contract, fracturing the paintlne. The paint film at the joint, if you think about it as 2 separate pieces, just stops square.

With a radius, the V jount that is formed can have some flexible V joint filler in it. Then the door is painted. In service any expansion moves the filler but the paint remains intact.

It's a great shame that, probably because of the way the responsibilities of different "trades" are organised, the people who design, build, install and paint/re-paint these details are usually all different, and working under intense time/cost pressure, information gets lost in the process.

I don't think I've ever seen a V-groove in this kind of situation that has caulk/filler/mastic in it - and of course, most, if not all, have a crack line in the paint at the bottom of the V.

Isuppose a V-groove might work better if it were angled upwards a few degrees, to form a slight overhang, so water is more efficiently kept away from the crack line.

Normally, with dissimilar materials e.g. timber and masonry the way to cater for differential movement is with some kind of stick-on moulding - I guess that would be another option to protect long-grain/short-grain joints like this, perhaps inset slightly. Another example of this kind of scenario being a weather bar on an external door.

 

[RogerS]

I'm with woody but I can see Robin's rationale. My thoughts were that (a) it was 'trendy (b) it could hide bad joinery. The downside as I saw it was that you now had two 45 degree slopes of end-grain to rot where before you just had any water ingress at the join. Which you still have in either.

 

[Trevanion]

I'm with woody but I can see Robin's rationale. My thoughts were that (a) it was 'trendy (b) it could hide bad joinery. The downside as I saw it was that you now had two 45 degree slopes of end-grain to rot where before you just had any water ingress at the join.

It started out as a way for the high-speed low-quality window manufacturers like Jeld-wen to get away with hiding badly fitting joints and not having to flatten the joints so they are flush, if you take a straight edge to the joints you usually find they're anywhere to 1mm out of flush. All it really was aimed at was making the product cheaper and faster to produce, not better. Then some clever bloke comes along and decided to put caulk in the joints at some point and voila, now we have V-groove filling products like Teknoseal 4009 which is basically expensive caulk. On two separate occasions I've seen this V-groove filler stuff crack, fail and peel off with seasonal movement, which as you said, it allowed water to ingress behind the paint into the end grain of the V-grooves and start blistering the paint off.

If done properly, the tenon shoulders on doors shouldn't crack the paint for many years unless somebody's been slacking on maintaining the paint.

 

[scholar]

100% echo the favourable recommendations for Accoya. I have used it just once so far for two asymmetric pairs of garage doors - in each case the largest was 2000 x 1400 ish - made out of 45mm thick accoya and 15mm Tricoya panels.

It is a somewhat overdue job to finish fitting these, but they have been stood in a damp garage for a couple of years and I am not sure they have moved more than a mm - I have little concern that the external performance will be anything other than very good.

Just a couple of practical points from my experience:
- be careful moving the assembled door - my (very heavy) large door suffered a small corner chip when manoeuvring it - it is acknowledged to be somewhat brittle - this was easily repaired and it is to be painted anyway.
- be careful sanding the face of Accoya because you can get a rippled or undulating effect as the pith(?) sands more than the [other bit]? You shouldn’t need to do much of this anyway as it machines beautifully and remains stable for assembly.

Cheers

 

[Steve Maskery]

Thank you all for your contributions. The ball is now in their court.
S

 

[Phill joiner]

I made all my windows and my front door in accoya 3 years ago now. They had morrells spray colour finish. Square flush joints, no v grooves. I've had no problems what so ever. The doors 1100mm wide x 2200mm high x 57mm thick. Arched top. The front of the house gets a full on hammering from the weather too. I'd recommend accoya. I wouldn't recommend tricoya for panels though. I've had a few problems over the years on clients jobs.

 

[Steve Maskery]

I'd recommend accoya. I wouldn't recommend tricoya for panels though. I've had a few problems over the years on clients jobs.

Thanks, Phill. What sorts of problems, please?

S

 

[Trevanion]

I wouldn't recommend tricoya for panels though. I've had a few problems over the years on clients jobs.

Nice to see I'm not the only one that's seen problems with the Tricoya! I mentioned in another thread the other day that I saw some doors with Tricoya panels that were sweating internally.

Was this the problem you had?

 

[Phill joiner]

I'd recommend accoya. I wouldn't recommend tricoya for panels though. I've had a few problems over the years on clients jobs.

Thanks, Phill. What sorts of problems, please?

S

I can only describe it as swelling really. Only in the corners of the panels.
This is the front door made from accoya.

 

[ColeyS1]

How can tricoya swell ???? I did several tests when I first started using it and even fully submerged for weeks the tricoya barely moved at all- from memory I think it was 0.1mm max on a piece 18mm thick.
Door looks good [WINKING FACE]

Sent from my SM-G900F using Tapatalk

 

[Phill joiner]

I think it was heat more than water. The door had been painted black and it was last summer, when we had those crazy temperatures. I changed the panels for accoya and no problems.

 

[mr rusty]

Over the last 2 years I have made 7 sash windows and a set of inward opening patio doors (56mm thick) from Accoya, and it is brilliant for external joinery - it doesn't seem to move at all. As others have said my experience is it machines well, but is brittle - I can understand hinge jamb splits if the door got caught by the wind.

I used Teknos Aquatop sprayed on with a HVLP sprayer, and it goes on beautifully. I used Teknos because many of the pro companies seem to use it e.g. Mumford & Wood (who also helpfully provide a lot of tech info on their products) - they would also make a door for you if necessary.

When glueing it up, you have to use PU or Epoxy. From the reports I found, just about everything else has poor performance.