rim joists with no sill plate, pics included


Old 09-29-10, 12:06 AM
Thread Starter
Join Date: Aug 2010
Location: TN
Posts: 27
rim joists with no sill plate, pics included

I inherited an old house and I'm attempting to fix it up a bit. I went to insulate the rim joists and discovered that there is no sill plate there. I'm confused. I have attached pics:

I was expecting something like this:

What is going on here? Thanks.
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Old 09-29-10, 08:21 AM
Join Date: Dec 2005
Location: USA
Posts: 3,188
I've seen old barns built on foundations w/o a sill but not a house. From the pics it looks like there may be some rot on one of the rim joists, other than that the framing looks solid. I'm curious, where are you located? My guess is SW.

Have you encountered much rot? I would probably try to get some caulk under the rim joist to cut down on air flow. Other than that there's probably not much that can't be done without some serious deconstruction. IMO if it has lasted this long it isn't worht the trouble.

Non PT lumber directly on a concrete foundation will probably make some people here faint.
Old 09-29-10, 11:18 AM
Join Date: Mar 2009
Location: WA
Posts: 1,167
The wood appears to be cedar or redwood; both are acceptable for concrete contact per Code. The missing plate usually gives the floor system a positive connection, held down to the concrete block foundation wall for winds and seismic shear forces transferred to the earth. There may be metal straps, mortared in the block cavities to the rim joist attached on the outside, under the diagonal board sheathing or just siding.
Wayne may be correct, even though no sign of water now. Was any faced insulation installed in the bays (stapled paper down on joist bottoms) to cause the water line on the right joist bottom? If fiberglass, this would explain the rim area (sun heated) wicking moisture from the wet concrete wall after a rain. The second picture is of a large knot at the end of a joist much bigger than acceptable size for today’s standards. This shows the builder may not have gotten a permit and used lesser quality wood in the structure and lack of a sill plate required by code.

Old 09-29-10, 11:50 AM
Join Date: Mar 2005
Location: USA
Posts: 6,126
I would put the construction to after 1960, since the block are a modern shape, but a few producers switched earlier to get away from the inefficient old pear shaped cores. It looks like Thoroseal on the walls, which is superior to DryLok.

I also was struck by the question "How is the house held down and prevented from sliding" because a sill is perfect for using anchor bolts. There may well be straps since the rim joist(s?) are in the center of the block and the cores are filled, so straps may have been used.

I would not worry about a knot or two in an area of very low stress and grading standards may have been changed.

The OP is from TN, which may be near the actual home location.

Old 09-29-10, 01:41 PM
Thread Starter
Join Date: Aug 2010
Location: TN
Posts: 27
Thanks guys, some great info here. I haven't seen any rot other than in the pic I took. There was paneling installed with a barrier of some kind underneath, foil looking but rips like paper (vapor barrier?) which would explain the water line on the joist bottom. These are actually pics of the garage ceiling which is in the basement, pics are from the back of the garage. The outside of this wall is underground, the house is built on a slope. Since there is living space above the garage I had ripped out the thin paneling and was going to replace it with fire rated 5/8 drywall. I intend on using "Mold Defense" type X drywall in certain areas such as where the water line is on the joist.
This stuff is almost twice the cost of regular fire rated drywall.

I'm going to take some more pics, the rim joists are actually sitting on the outside edge of the block and not in the center. It only looks like the rim joists are sitting in the center of the block because these blocks are thinner than a standard block.
Old 10-05-10, 05:08 PM
Join Date: Aug 2009
Location: USA
Posts: 4,941
Houses not being bolted to the foundation isn't unheard of. It's definitely not a practice of modern building. I havn't looked for them yet, but I have a feeling that my house isn't bolted to my foundation. built 1928.
Old 10-20-10, 07:34 PM
Join Date: Oct 2010
Location: us
Posts: 3
how much work to build it right?

have you considered lifting house?
there is no way to tell from pictures
but a single story house can be lifted
on one side then the middle then the other
side without much chance for cracking
when the total lift is 1.5 inches.
actually lift 2 inches to put in new pressure
treated sill plate with anchor bolts (with concrete filled block)
and continuous foam sealer. lift and let down on new sill
but leave corners that 1/2" higher until you get the end sill plate
installed. you can go back and lift off that shim as last step.
bottle jacks are $10 to $15 each or you
could use car jacks even screw type.
you will be proud to have a better built house
and not worry about the rot, air loss, wind loads,
termites, capillary action or mold.
why we build every time the same? why not?
just remember when the house inspector convinces
the buyer to walk away or have you do this work
before selling is not a fun job to rush.
it is not rocket science and not the anything back
it is always nice to be proud of you house.

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