I’m a bit out of my element here….I usually lurk over at the Knots forum. But here is a question for the masons. I plan to build a low (about 3 foot high by 2 foot wide) mortered stone wall to support a couple of turned wooden columns. The columns will in turn support a wooden pergola that will be anchored into the side of my house on the far end (about 12 feet away). The question is: Do I need to dig the stone wall’s footer all the way down to the frost line for the full length of the wall? or can I just dig down to the frost line for sonotubes and pour a sort of box beam out of concrete connecting the tube-filled concrete together? Obviously, I’m a little worried about frost heave and its effect on the pergola connection to the house and the top of the wooden columns. I live in southeast Pennsylvania.
Does this make sense to anyone? What would you do?
–Joejoe
Replies
JoeJoe,
Either way would work, but I reccommend haveing an experienced local bulder or engineer help you with the sonotube design.
If you trench the whole wall, just well compact the bottom of the trench. You would not need to mortar the stones under grade. You can use coarse (-4" or bigger) gravel below grade.
I think that full trenching is cheaper.
Thanks for the advice SamT