Does wood ever stop expanding?

[martinka]

My garage doors are made from pine floorboard and look great. I sprayed them with Thompsons clear water seal, but the doors seem to be forever expanding. I have already removed about 1/4" from the doors but they are stuck yet again. Rather than keep moving the padlock hasps, I have elongated the hole, and you can see on the photo how much they have moved. In fact, you can hardly see the join between the doors they are so tight together. I wish we could get some decent weather to let them dry out so I can paint them.
(Not really looking for answers, just having a moan, though suggestions will be taken on board)

 

[lurker]

Wood only expands as it gains moisture
So.......if it does not expand & contract (as the humidity rises & falls) it must be getting wetter & wetter
IMHO its a symptom rather than a cause in your case.
You need to investigate why.

 

[Sheffield Tony]

IMHO its a symptom rather than a cause in your case.
You need to investigate why.

Presumably because it started out as dry floorboarding for internal use, and is now part of a garage door exposed to the elements in winter ? IME, no kind of finish seals wood enough to prevent seasonal movement. The question that we can't answer from the photo, is has enough been done in the design of the doors to allow for and mitigate the effects of the movement ? I'm guessing that that is where the problem lies.

 

[martinka]

IMHO its a symptom rather than a cause in your case.
You need to investigate why.

Presumably because it started out as dry floorboarding for internal use, and is now part of a garage door exposed to the elements in winter ? IME, no kind of finish seals wood enough to prevent seasonal movement. The question that we can't answer from the photo, is has enough been done in the design of the doors to allow for and mitigate the effects of the movement ? I'm guessing that that is where the problem lies.

I must say the guy who made the doors for me didn't, in my opinion, leave enough gap between the doors, so I planed some off, three times now. If I keep this up, come next summer when/if they shrink again, I'll be able to get in the garage without unlocking it.

When it stops raining, I'll remove the doors and take some off the outer edge as they are tight against the frame now. The doors are stepped where they meet, so I can afford to take some more off there too without there being a gap.

 

[Beau]

Wood will expand and contract for ever to fit the RH unless completely sealed from moisture. Sounds like you have very dry wood in a damp environment. It will settle down once it reaches equilibrium with surrounding RH

 

[Fitzroy]

There are charts that describe shrinkage/expansion with changing moisture content. There is also an online tool you can use, see below. The issue you could have is the boards could have been very dry in a home environment (moisture content could be <10%), compare this to air dried wood (moisture content could be up to 20%). Putting these numbers in the tool below (10-20%) a 60" door could move by 1"-2", depending on species.

http://www.woodweb.com/cgi-bin/calculators/calc.pl

Was the wood conditioned before making the doors, ie left to acclimatise to being outside, or was it nice and house dry when they were made?

Regards

F.

 

[martinka]

Was the wood conditioned before making the doors, ie left to acclimatise to being outside, or was it nice and house dry when they were made?

Regards

F.

The wood was in the rafters of the garage when I moved in to this house, in April. The house had been rented out for the last 3 years, so I assume it had been there for at least that time, and possibly 7 years as major alterations were done to the house in 2009. There is a 6ftx10ft shed built from the same wood which is OK, although that has been painted with Ronseal fence paint.

 

[Fitzroy]

Well that's shot my theory out of the sky! I'd assumed it was a relative humidity effect of outside vs inside.

One would assume that driven moisture, rain, would have a similar effect however in this case a weather resistant coating should make a difference as i'll prevent the rain wetting the wood.

F.

 

[John Brown]

Our gate, from the street to our yard, has been planed every year for the last 4 years, and currently looks like it needs doing again. If it carries on this way I may open a timber yard and sell off the surplus wood that seems to be created out of nothing.

 

[kevinlightfoot]

If you really want to understand how wood reacts not only to the elements but the effects of kilning ,.air dying and relative humidity you could do no worse than obtain a book called Understanding wood by author Bruce Hoadley it comes up now and then on eBay but it is quite expensive if you buy a new copy.Your timber can only expand to its saturation point but it is unlikely to reach this condition in this country and expansion and contraction is a thing you have to live with.I do not know of a finish you could use to alleviate your problem perhaps others on the forum could help .

 

[Freddyjersey2016]

Don't know the answer to the expansion problems - but I would suggest
a) Does the door frame have a drip head try and keep water off the top of the door - water penetrating into end grain will cause problems
b) paint the doors both sides with a wood preservative like Ronseal or Sadolin Wood Preserver asap - pine rots very easily otherwise if it is regularly wet
c) Coat the doors both sides in a microporous woodstain like Sadolin Classic - BUT it cannot be applied to wet wood, and temperature needs to be at least 8C for it to dry (you can apply it in colder condition but it will dry very slowly)
Suggest erecting a plastic tarp tent in front of the doors to let them dry out

 

[screwpainting]

Looks like a great advert for linseed oil paint or just plain linseed oil to me, all modern exterior paints seem to do is sit on the surface and try to waterproof the wood and as soon as that skin is broken water gets in. Linseed oil makes the wood water repellent if it is soaked in at its driest state. I am lately of the opinion that you need to make exterior projects water repellent prior to painting or staining and only an oil will penetrate and do that unless you use an industrial process.

 

[ED65]

Linseed oil makes the wood water repellent if it is soaked in at its driest state. I am lately of the opinion that you need to make exterior projects water repellent prior to painting or staining and only an oil will penetrate and do that unless you use an industrial process.

But oil penetrates the wood at most a bit deeper than stain, which is to say not very deeply at all. And then on top of that drying oils, once cured, form quite a porous layer.

Linseed oil, and linseed oil finishes, actually derive their benefit from this: they allow the wood to gain moisture and then lose it readily, rather than trapping it in the wood the way a non-porous film does where the water can only evaporate very slowly through fissures, pinholes or other gaps in the coating.

 

[John Brown]

If you really want to understand how wood reacts not only to the elements but the effects of kilning ,.air dying and relative humidity you could do no worse than obtain a book called Understanding wood by author Bruce Hoadley it comes up now and then on eBay but it is quite expensive if you buy a new copy.Your timber can only expand to its saturation point but it is unlikely to reach this condition in this country and expansion and contraction is a thing you have to live with.I do not know of a finish you could use to alleviate your problem perhaps others on the forum could help .

I have the book somewhere. Maybe I could make a new gate out of it.

 

[sawdust1]

This is why i hate making doors and windows.
Having to return to customers who's windows and doors need to be planed off and repainted
is a real pain as i can't charge for this, luckily i don't make many. Saying that i've got 8 to do
in the next couple of weeks.
Does not matter what timber is used softwood or hardwood they all do the same.
People think the wood will shrink back to the starting point once dry but that is simply not
the case.

 

[skipdiver]

I have a pair of FLB doors on my workshop and every winter they start to swell and get harder and harder to open and shut. It also gets harder to lock them. I did the planing down thing but as mentioned, in the summer when they shrink right back, the gaps were getting too big, so i thought about it and i chopped the hinges in a bit more. I put packers in the hinges in the dry months and take them out again when the doors start to expand, which has been in the last few days with all the rain we've had. The doors have had umpteen coats of exterior finish but still move a lot over the seasons. I have also expanded the chop outs for the lock keeps and have to move them forward in the winter and back again in the summer. 5 mins with a cordless drill has them working again. Not the ideal situation but it works.

 

[Doug71]

When you look at old barn doors and stable doors they are often fitted in front of the frame so when they swell and shrink it doesn't matter, the old boys knew what they were doing, I know this is not practical in most situations though.

I have started using Accoya more and more, very expensive but doesn't move. If you can convince the customer to spend the extra it saves problems later on.

Doug