Repairing Cracks in Old Church Pews
Swings in heat and humidity have opened up cracks in some old pews. Furnituremakers suggest practical repairs. September 26, 2006
Question
I reviewed a local church sanctuary over the weekend after being asked to look at their cracking pew backs. The bench seats appear to be just fine, but numerous backs have longitudinal cracks in them of varying degrees. Some are at the glue joint and some are in the individual boards. Age is unknown, but estimated by congregation members at 100+ years. They are red oak.
What I am thinking for repair is to route very straight troughs across the crack, say 3" wide, then lay in thin new stock, sand, stain, finish, and re-install. What other considerations should I make regarding this potential work?
Forum Responses
(Furniture Making Forum)
From contributor F:
You might want to determine what is causing the splits to occur. If it is a matter of elongating some screw holes to prevent further cracks, you would be doing them a good service. I think your plan to inlay wood over the splits is as good as any. I would run the repair strips full length for looks (not a stopped patch with a butt joint). Hard to say without seeing the construction, but I might try to work glue into the cracks and clamp if the design permits that. Again, try to eliminate the cause of the splitting (usually cross grain restriction). In the case of a failed glue joint, glue on glue is a bad idea, so disassembly and removal of the old glue would be the proper way.
From the original questioner:
I agree with the full length patch. That, too, was my initial thought. I can't say for sure on the cause. I would attribute it to age and humidity, or lack of it. There is also a cross grain situation where the back meets the end panels/arm rests. I will have to look again to see how long the cracks are and where they occur relative to the ends. I was told there is concern about removing the pews for fear of them falling apart (they seem sturdy to me, and they are also screwed to the floor, presently). But this would be a far costlier fix on site, I believe.
I will also need to check to see if the hymnal troughs are contributing. Those are screwed, but I don't think they span far enough that movement would be severely limited - not enough to cause cracking, anyway. I think the cracks have been developing for quite some time and only now (I was told after a very thorough cleaning) have they really presented themselves. And they pinch backs of arms, etc. Thanks for your thoughts.
From contributor F:
Since church budgets are limited in a lot of cases, and the work might have to be done on site, another way to do it is to fill the cracks with colored epoxy. Might blend in better than fresh wood patches. Sounds like a tough job if you need to have it all complete between two Sundays.
From contributor W:
I'm trying to picture what you're describing, and wondering whether there isn't some way to deal with the expansion (a likely source of the problem) and then create an invisible repair using a hidden spline. Having a hard time picturing this, though, so the suggestion/question may be way off base.
I'm also wondering whether the material was very dry when these were first constructed. Given their vintage, perhaps the moisture content was higher than we know is safe today, and contributor F is exactly on the money with regard to the hardware.
From the original questioner:
Below is a sketch of an example pew. I also thought about the epoxy, but only briefly. Probably stems from the lack of product close by and my limited use of it.
Schedule-wise, this would be a two or three pew-at-a-time deal (and in the spring, for that matter, if I do it), with no requirement to be done between Sundays. If I do it on site (would rather bring them back to my shop), I'd be constructing a tent of sorts in the sanctuary. Hopefully, it won't be that way.
From contributor F:
My instinct is still that something must be restricting cross grain wood movement to cause these in the field cracks. I would be interested if anyone has knowledge of other logical reasons besides restriction that would cause it. I would probably rule out moisture changes, since the pews are so old and always in a heated space.
From contributor W:
Given the financial straits of many churches, don't assume that any church is a heated space when not in use. Many of them keep the space barely enough above freezing in the winter to avoid bursting the pipes. They tend to be large spaces, old, not well-insulated, drafty and hard to heat. The same issue in reverse applies to church spaces in the summer. They aren't air-conditioned during the week in most cases, and so the temperature and humidity will likely yoyo up and down week after week in warm weather as they are cooled down for services on the weekends, and allowed to heat up during the week to save on air-conditioning expense.
From the original questioner:
Right. The heated space is what I think has contributed to it. I think, per chance, it has been overly warm and dry in the winter time and certainly dry and cool in the summer after the advent of a/c, whenever that was. I can concur on the restriction. Looks like the end panels may contribute to that. On top of that, I think the less-than-ideal conditions, climatologically-speaking (indoors, that is), have also "cooked" the wood.
I won't have time to do so real soon, but I think I will ask to see if I can pull one of these out - maybe even before I have the job 100% - to do a little more investigating as to what has caused this to happen.
Good points on the fluctuation throughout the week.
From contributor D:
Upholstery and a humidifier ought to do it.
From contributor L:
The church has a limited budget, and the complaints relate to pinched arms rather than the cracks themselves… Could you prevent the pinched arms by easing the cracks' edges rather than by patching them?
From the original questioner:
Boy, that's a good point, too. I did get only the sense about the pinching. As I mentioned, the pews do seem plenty sturdy to me. If pinching is the only concern, that would be cheap and quick and probably (bite my tongue) they could do it themselves.
There is also talk of working on the floor. Not part of my work, as I don't do floors, but they want to unify it, color-wise, or refinish it, or something. I suggested a really good cleaning, a bit of light sanding, and going back over with clear, leaving the age and patina. Too much history and character to re-do this floor, not to mention the cost and mess. But the floor is a separate issue entirely. I just threw that in for conversation. Several ideas here. Glad I put the question out. Thank you, and I'll consider more input should anyone care to.
From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
We do have to remember that dry oak is very strong, so initiating new cracks is really quite difficult, even with expansion and shrinking that will occur as the RH changes. Also, any finish will retard the speed of the MC change. I believe that chances are really good that these cracks are old cracks that are re-opening. If possible, look inside of them for stain or other finishing debris to prove that they are old. If they are indeed old, then they will open if the RH in the church is kept lower than normal. Is it possible that the heat is now kept on for a longer period of time? That would do it.
As far as repair goes, you need a rigid material. Otherwise, when the RH increases, the filling will be squeezed out. As the stresses will be the same, any repair must be very solid, so the idea of using epoxy, which bridges a gap and maintains strength, is great. I would use a wood spline with epoxy adhesive.
I was involved in similar cracks in pews, but they were in the seat in a US Marine chapel. The cracks would open when everyone sat down. The problem was that the last person to try to stand got pinched and clothing got caught... True story.
From contributor H:
I'm wondering if putting a butterfly patch on the back of the pew in addition to cutting in new wood over the crack would be beneficial. Help to stabilize it so that there is little if any wood movement.
From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
One additional thought. Make sure any repairs are done when the wood is very dry (not abnormally dry, however, as then you will get swelling and that can be a problem too). This will give you the biggest crack and it will not have a tendency to get any bigger.
From contributor C:
I can address the cause of the splitting from your description and the location. If it is a church with a limited budget (redundant?), then they are likely shutting down the heat for extended times and then turning it up in anticipation of when the place is used. This will cause swings in humidity that will be exacerbated by the parishioner's exhaling a bunch of "amens" or singing a lot. The preacher could also be causing these folks to squirm and/or sweat a bit - or a lot. He could even be turning up the heat to enhance the sweating effect. You might suggest a bit of moderation. There could even be liberal use of water sprinkled about, adding to the humidity.
I would think that if these folks are getting pinched by the pews, they would be more likely to pony up the extra bucks to repair the pews. Talk about direct action/reaction. Or, is the message about pain in this world traded for something better in the next? It's a miracle that splitting pews is not a larger problem than it is.
From contributor T:
When metal cracks, a solution is often to drill a hole at both ends of the crack so there is no pathway to continue the crack in the direction it moves. Maybe this would also work in wood.
From the original questioner:
That may explain the oddness of seemingly random installation of dowels in at least one pew. I couldn't see that they related to anything, but perhaps closer examination would reveal someone's previous attempt at stopping the problem.
From contributor V:
I wouldn't advise repairing in Spring or Summer. Cracks like that result from shrinkage, and may originate from invisible or seemingly insignificant checks or shake present when wood was milled.
How old are the pews? Do they predate installation of central heat to the building? Were the pews refinished at anytime, especially near the appearance of the cracks. The back pieces of the pews seem to ride within a slot milled into the sides. Older pews would be of a frame and panel design. Do the top rails function, along with the join to the seat to frame the other pieces? If so, an earlier treatment might have worsened the situation.
Here's the scenario I envision: church gets a new heating system, or tighter windows, which dries the building. Church pews shrink due to MC change and cracks appear. Enter the deacons, who patch the cracks and brush on some new varnish during Spring spruce up. Come Fall, the problems return, but now worse because the varnish the deacons used was a cheap polyurethane that penetrated the joints between the boards and solidly glued components intended to float in accommodation of MC fluctuation. Now, every Fall the panels endure a rack that places them in cross-grain tension.
The cheapest way out is to fill the cracks with an elastic material in the dead of Winter when the sanctuary is driest. There may be an epoxy for this, but I can't say. Next option would be to try to free up or create expansion joints between the top and seat rails.
From the original questioner:
Neither the seats nor the backs are frame-and-panel, but good points. I think I will present a range of prices and perhaps suggest a trial of a couple different methods on a couple of their lesser used (and hopefully smaller) pews. Thanks, everyone.
From contributor U:
I thought the butterfly patch was a clever solution. Rout and install, use a contrasting species for looks, ease over any splintery edges in the crack and there you go. I'll bet the intention of the parishioners is to simply make Sunday worship more bearable and the patch would do that. Tell them a patch on the crack saves a patch on their pants.
From contributor P:
At 100 years old, determine where (if any) the restriction is, and alert clergy to limit very wide swings in temp. Repair - the cracks will not contain finish mid board. Use Titebond and clamp pressure - not too much. If a small gap continues to exist, leave it - leave room between your clamps to rout a dutchman (butterfly) across the crack (make a jig and it can be easily done on site - the butterflies can be cut in the shop). A la George Nakishima, apply butterfly(s) in one or more places depending on size of crack. The butterfly dutchman will be visible. It is and will always be an acceptable, easy, practical, skillful, and responsible repair in situations where antiques of this nature are involved. Make sure your client is educated on this fact before you commence.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor J:
I am dealing with similar cracking on curved pew backs of a similar age. On first glance they appear to be solid oak, but after removing the cap rail on top of the backs reveals that these backs are bent laminations; three plys each about 1/4" thick with two running lengthwise and one running vertically. A failure of the hide glue has allowed delamination of the backs and this has allowed the "cracking" to occur. They don't feel strong or solid, rather they feel flexible and are springing back to being strait like the original boards. I'm still devising a solution that will likely involve opening up the layers, scraping/sanding away old glue, re-gluing, and clamping using a load of customized culls to recreate the angle to the seat, the vertical profile of the back, and the plan view curve of the back.
