Using Pressure Treated Wood For Floor Joists

The ends of wood girders entering into masonry foundation walls with less than 1 2 clearance.

Using pressure treated wood for floor joists.

Until a few years ago the irc didn t have deck joist span tables. The chemicals used in pressure treating lumber including fire retardant chemicals are corrosive to bare steel and could weakend joist hangers potentially leading to collapse during fire. The allowable stresses of pt lumber are lower than non treated lumber which means it can not span as far. But the 2015 irc included a new one table r507 5 that will make it easy for deck builders to spec a joist size for a given span and joist spacing.

Kiln dried treated carcassing 9 width. Any wood on a foundation wall and is less than 8 from the exposed ground. This treated lumber is bolted to the foundation and the floor joists typically rest on it. 45 mm 1 70 mm 1 95 mm 1 120 mm 1.

Also pt lumber is corrosive so connections need to be such that they resist corr. You can watch an informative video that shows a treated lumber sill plate and how it rests on a foundation. Pressure treated lumber is also essential for exposed areas of the shed that may be exposed to the weather and water. The first piece of lumber commonly attached to the top of a house foundation is often called a sill plate.

The table includes spans for. Fsc standard kiln dried regularised c16 treated carcassing 220 x 45mm. Yes pt lumber can be used for framing including floors. Pressure treated wood is required whenever you attach framing lumber or furring strips directly to concrete or other exterior masonry walls below grade.

In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place. Use pressure treated plywood that is attached to floor joists with exterior grade screws. Take some extra time and jack the damaged area up so that the new lumber doesn t need to be notched. However doing this does not fix the slant that the floor has taken since the old joists got damaged.

Girders in crawl spaces are closer than 12 to the ground. Floor joists in crawl spaces are closer than 18 to the ground. Be sure also to use ground contact pressure treated wood for any framing that will touch the ground. Exterior grade nails can be used but heavy traffic will cause them to slightly flex out and eventually.

A floor close to the ground won t last as long using non pressure treated wood. Cleaning equipment pressure washers vacuum cleaners dryers floor cleaning. Note that this requirement is only for exterior walls as these may wick moisture onto the lumber. Perry mastrovito design pics getty images.

Just click here sill plate video.