About two years ago as part of my residential renovation, I installed a pair of old (100 years?) cypress doors in my residence that I bought in New Orleans. Each door is approximately 30″ wide by 7′-4″ tall. The 1-3/4″ thick doors are mostly glass, with a simple 4-1/2″ cypress frame on all sides, with the exception of the bottom rail which is 13″. These handsome front doors are well protected from rain, but are subject to the mid-Mississippi environment. (High humidity)
Over the past year I have noticed that one leaf is warping at the upper latch edge. The bend is towards the inside and measures about a half inch. The direction for the bend makes sense considering the inside climate is conditioned (dry) and the outside is exposed to the Mississippi humidity. Based upon the older doors, I built 16 matching cypress doors that are also installed in the renovation and yes, there has been a small amount of movement in some, but nothing like the older front doors. I would like to hear comments on possible ways to correct this problem as well as suggestions to prevent this from happening again.
P.S. Reflecting on my own comment above, I recall that when the doors were installed, I instructed the contractor to be sure to seal the top and bottom edge of all doors. Since then I have assumed that this was done since I was very insistent. However, considering other things, I am not sure this was done, but I will certainly check.
Replies
This is classic humidity warpage, as you guessed. Sealing the tops and bottoms helps, but most of the moisture gain/loss is going on through the face of the doors.
The type and integrity of the finish will have a significant impact on how much they warp, but the age of the wood and how fine-grained it is is likely also a factor.