# Ipe Pergola - Sliding Dovetails - Water Protection



## TheOtherMrRogers (Jun 5, 2012)

My friend and I have a question for the Lumberjocks community.

He's buiding an Ipe Pergola. It looks AWESOME!!! He's using stopped sliding dovetails,


















open at the top, for the jointery of the beams. Very nice fitting, he's doing a great job.

The joints are nice and tight.

We live in a Northern State, and we were wondering about the risk of water seeping into the joints, freezing and causing damage.

So here are the questions:

1: Should we be worried about freezing?
2: What actions, if necessary, should we take to protect against freezing damage?

Any info / advice would be appreciated.


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## AandCstyle (Mar 21, 2012)

I have no experience with this so take my thoughts with a large grain of salt.

1. When the water gets into the joint and freezes, it will about double in size so 1/32 gap filled with water will become 1/16 ice. Is that enough to do anything to the joint?
2. Clear silicone caulk would prevent any water from getting into the joint if it is well done.
3. Drill a small weep hole into the bottom of the joints so any water has a way to drain out and ice has room for expansion.
4. Bottom line I don't think it will cause any problems, but maybe it has never been done that way for a reason.


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## Ger21 (Oct 29, 2009)

I doubt that freezing water would do any damage. If the joint is decent, there shouldn't be hardly any water in there anyway.


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