Jim Robinson
04-29-2014, 04:49 PM
Venting is definitely not my strongest area, so see if this makes sense.
This is an older house, built in 1948. Every other house in this neighborhood that I inspected has a large 3" or 4" vent on the roof for the bathroom, and a smaller vent for the kitchen. This house had two 1.5" vents on the roof. One was above the kitchen, and the other was above the bathroom. There was no reducer visible in the attic, so it doesn't look the larger vent ever existed.
This is a duplex, and the other bathroom does have a 3" vent on the roof, as well as the smaller 1.5" vent for the kitchen. Both drains are tied together under the house, and there is one main line leaving the crawl space to the street.
I thought that for a toilet vent, the minimum size is 2". The toilet, sink and tub vents are all tied in at the same wall, so it has to be venting through the 1.5" pipe.
This is an older house, built in 1948. Every other house in this neighborhood that I inspected has a large 3" or 4" vent on the roof for the bathroom, and a smaller vent for the kitchen. This house had two 1.5" vents on the roof. One was above the kitchen, and the other was above the bathroom. There was no reducer visible in the attic, so it doesn't look the larger vent ever existed.
This is a duplex, and the other bathroom does have a 3" vent on the roof, as well as the smaller 1.5" vent for the kitchen. Both drains are tied together under the house, and there is one main line leaving the crawl space to the street.
I thought that for a toilet vent, the minimum size is 2". The toilet, sink and tub vents are all tied in at the same wall, so it has to be venting through the 1.5" pipe.