Another foundation question

[devildog]

When building ablock crawlspace foundation,I understand I have 2 options for the center beam.

1. Build block piers level with outside walls and attach floor joist w/hangers to the built up center beam or
2. build block piers lower than outside walls w/ beam pockets, so beam is level w/ outside walls. And floor joist lap over beam.

My question : Is one of these better/preffered over the other, is one method less expensive. I really dont think there is ,I just like hearing your opinions. I like the first one,only because the piers being level w/ the walls sounds right.Silly right? Still thinking things through. Darrell

[Don_P]

In #1 you are hanging the floor on nails using a hanger (which has a cost) and is an inferior support to wood resting on wood. It also forces plumbing and ducting to go under the girder rather than having a clear shot across the bays.
In #2 you are lowering the headroom. The joist bearing surfaces are all at the same level, sills and top of girder.

[n74tg]

Most of my center beams (I have two) sit below the floor joists.  However, in about 1/4 of my crawlspace area I have a slab poured, so I want the beam up higher (better headroom).  It is there that I hung the floor joists off the side of the beam.

While this is not a great pic, it does show the higher beam portion in the rear of the photo.  One beam sits on top of the other where they join.  The two beams are plated together (3/4" plywood) on both sides of the joint and connected with multiple screws and nails.

[devildog]

Question#2
Is a cap on top of block foundation needed, what benifit would it have?
I got my first bid today,$4300,this includes all materials and labor. but does not include backhoe to dig footers,my septic guy will do it for$85 hr.
He said he,d reduce price by $280 if I didnt want the cap. WHat do you'll think.

Heres the final plan:

[Don_P]

I've never worked off of caps that I recall, just filled cores on at least the upper course to prevent termites from coming up the insides of the blocks. If you are doing dropped girders there need to be pilasters or pockets and elevations for the piers noted. Don't forget a crawlspace door, not under an exterior door, and vents.

[devildog]

Don P,
how do you fill the upper coarse without doing the entire thing. he never mentioned filling the core, but becase he mentioned caps I asked how would you put in the sill anchor bolts, and he said he would put them thruthe joints. is this right?

Darrell

[Don_P]

Yes the J bolts would go through the joints but should still be in a solid poured core. I've wadded up newspaper and stuffed it down the cores to make a bottom for the cap pour. I'm a poor enough mason that whenever I've done small jobs I just pour them solid.

If the crawspace door can be in an end it might be easier, that way you don't need to worry about carrying joists over the opening.

[n74tg]

Dog:
I have a bond beam on top of my block walls.  In the URL below are two pics of how I blocked it off so concrete wouldn't go all the way down.  You could use this idea on your project too.

http://n74tg.blogspot.com/2007_01_21_archive.html

[devildog]

Don P, thanks I am going to havethem put opening on the end.

n74tg, that was a good idea. I dont know if they are even going to do a bond beam,I guess I need to talk to him in greater detail and after hearing you and others mention bond beam leads to .....

Question #3: do you need to have a bond beam on a crawlspace? To be honest, I thought they were only for basements/ tall walls. Is this something I need? Its only 6 coarses.

Darrell