Supporting floor joists

OK... so I have come to the point in the projects (and winter is coming) that I feel like I need to get a start on some more support under the house. I will attach a few pictures although, they arent really good. currently there are some cinderblocks under the house supporting some joists. There is no center beam supporting each joist, I am thinking becuase of the HVAC ductwork.... The only thing I know to do is to measure out sections from point A to point B, put some 2x4x8's together pour some footers for a jack. Here is the kicker though.... I cant do it down the center of the house... the ductwork is in the way... so, I was thinking that maybe I should support on each side of the ductwork.... I would like to do it solid enough that the possibility of me going back under to redo it anytime soon will be slim. Any thoughts or suggestions?

As a side note and another question... I would like to put down clear plastic but how am I going to do that since there are already cinderblocks in the crawlspace?

here are a few pic, the under the house pics are taken from the crawl space door in the pic of the side of the house

The third picture shows the HVAC duct running across the floor of the crawlspace and under the floor of the house

The absolute best placement for support under a home like yours is directly under the walls. The natural impulse is to go directly to the center, but directly under the walls is far better. A doubled or tripled 2x8 would yeild a far better result than any number of 2x4s nailed together.

As for laying plastic under the house, I usually cut the plastic straight to the nearest side and use an office type stapler to "stitch" the plastic back together.

Putting some duct tape at the plastic joints to hold them first...then staple them together holds everything really well.
Also when you clean that space out please...wear the best safety suits and good cartridge FILTERED masks you can buy. Mouse droppings carry hanta virus and others ...as you probably already know...being a nurse. And replace that insulation...paper faces the heated space always.

FHI Decks & Windows said:

What size joist do you have and how far do they span?

Click to expand...

2X8-10X30is from what I can see......, I didnt want to crawl under there today, but I wanted to answer your post in response to mine.....