The "sap" oozing from your deck boards is a natural product of the wood...... actually called pitch.
Your deck wood is probably made of a member of the conifer species ...... likely pine ..... which have large pitch pockets.
When the wood gets hot enough it melts and runs out of the lumber .
Properly kiln dried lumber that has been heated to more than 160 degrees solidifies the pitch usually does not suffer from this problem. Likely the lumber used on your deck was either not kiln dried or wasn't dried at a high enough temperature to cause this solidification.
There's not a lot you can do about the problem at this point except live with it. As the deck heats up in the summer pitch will continue to run from the boards.
There is no sealer made that can contain it under these conditions.
But the news is not all bad ........ a bit of turpentine on a rag will remove it quickly and eventually the pitch pockets will run dry.
Hope this helps.
Last edited by canuk; 09-22-2008 at 08:08 AM.
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