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shrinkage in pressure treated post
i'm working with a homeowner restoring and repairing an old house. in the basement we re-supported the main floor girder with (3)-8x8 pressure treated posts. another contractor at the site bought up the concern of shrinkage. the posts are about 7 feet tall. i'm looking for info on an approximate magnitude of shrinkage in the longitudinal direction.
shrinkage for green wood in longitudinal direction is about 0.1% - 0.2% so we are talking about an 1/8". i'm telling the owner, it's a valid point....but not a concern.
your thoughts, links, opinions appreciated.
iron-mon
shrinkage in the longitudinal direction should be next to nil... possibly in the order of 0.1%
dik
the o.1 - 0.2 figure is from a moisture content of 30 % to oven dry, a moisture content of 0. generally longitudinal shrinkage is not of a concern. i would not worry about it.
the other question would be is pressure treated wood required. if the basement has a concrete floor by using a steel base plate 1" thick, you probably do not need treated wood.
the use of untreated wood would be a cost savings.
rarswc, that depends where the house is. in some warm climate areas, all wood is pressure treated for termite protection.
location is the greater philadelphia area.
and i do think it is prudent to use either steel (my first choice) or treated wood for posts in basements. |
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