Seasonal expansion in door

[petertay15]

The entry door is 1.75 thick. The lower panel is 22” made of 5 boards glued together, beveled to look like car siding. Panel is joined to doorframe with T&G. The wood is ash, so not lots of expansion, but northern Illinois gets lots of RH change, and temp range from 90 to -20. Does anybody see a problem here with air intrusion?

[jteneyck]

Peter, I no longer would build an exterior door that way.  If the panel ever cracks you are stuck since it's captured in the frame.  That happened with one of the doors I made and it was a real pain to fix.  It would be much better to use the traditional approach of holding the panel in place with moldings.  They can be removed if needed so the panel can be replaced, or refinished.  You can minimize air intrusion by running a small bead of caulk between the molding and panel.  

As for the panel itself, it would be better to use two, back to back panels, rather than a single panel.  That way, the inside and outside panels can expand/contract independently.  90% humidity outside and 30 - 40% on the inside during the Winter puts a lot of stress on a single piece panel.  Single panel or back to back, I do not favor full width panels.  I know it's traditional, but I see a lot of cracked panels, too, so clearly it can be a problem.  The expansion/contraction is automatical reduced by half if you design the door with a center muntin (stile) and use two panels.  

John

[petertay15]

Fortunately, most of the job is still in the planning stage. All three of your suggestions are worthwhile: center muntin, frame, and two layers of wood. The two-layer idea is excellent. Thank you!

BTW, I ordered Weldwood Plastic Resin from Amazon, the only place I could find it. Fortunately, I had been warned to check the (unknowable) date code. I called DAP to ask about it, and they said the can is way out of date, do not use it. --Peter

[jteneyck]

Fortunately, most of the job is still in the planning stage. All three of your suggestions are worthwhile: center muntin, frame, and two layers of wood. The two-layer idea is excellent. Thank you!

BTW, I ordered Weldwood Plastic Resin from Amazon, the only place I could find it.  Fortunately, I had been warned to check the (unknowable) date code.  I called DAP to ask about it, and they said the can is way out of date, do not use it.   --Peter

Well that's interesting.  I've been getting my PRG through Amazon for several years now and never had a problem.  I've never checked the date code, however, but can tell by looking at it if it's OK to use.  Good stuff is lighter in color and pours smoothly.  Bad stuff is darker and is more granular.  

If you've never used PRG before I'll offer a couple of tips.  The mix ratio is 5 parts glue to 3 parts water by weight, 5 parts glue to 2 parts water by volume.  The new 4.5 lb container I got a few months ago says 5 parts glue to 2 parts water by weight and by volume.  I don't know how or why that happened but it's wrong; it should be 5 parts glue to 3 parts water by weight.  

It's easy to miss the critical mixing instruction that says to add the dry glue, all at once and without stirring, to 2/3's of the water. Do NOT add the glue a little at a time while stirring or you will get lumps.  Dump it in and then stir it.  Once that is a smooth thick paste then slowly add the remaining 1/3 of the water while stirring.  

Let the mixed glue sit for at least 5 minutes and then remix it before using it.  

The spreading rate shows 40 square feet per pound of dry glue.  I've never been able to get adequate coverage at that rate, so I use 30 - 35 square feet per pound depending upon how porous my substrates are.  A rubber ink roller is the best tool I've found for spreading the glue while minimizing waste.  Foam paint roll covers work great but waste a lot of glue.  When using the rubber ink roller I mix 10% more glue than the calculation says is needed.  Soap and luke warm (not hot) water will clean the glue off the rubber roller while it's still wet.  

Hope that helps.  I'm sure you'll find what works best for you.  

John