This is a view into an exteror wall at the back of my home. The house is 1920s balloon framing. Behind that spray foam is a rim joist along the inside edge of the foundation wall. That rim joist was “repaired” by a shady termite company just before we bought the house. The repair cosisted of sistering the rim joist from inside and filling the gap between the new wood and the foundation wall with hydraulic cement. I opened this hole (in the back foyer) attempting to seal a draft and discovered the attached scene.
The vertical post in the foreground has been chewed away about 5-6 inches from the concrete block foundation. You can see splinters of wood filling the hole in the block. The edge of the horizontal beam is, I beleive, the center beam of the whole house. I’m no expert but it doesn’t look like termites to me. You can still discern an edge to the lumber, so it appears that’s where the beam is supposed to end. But the driftwood-like appearance concerns me, obviously. Is it some kind of rot?
Repairing the vertical post seems pretty straightfoward, but the edge of the beam has me worried. I’m here to pick the brains of the genius builders of Breaktime… how would you approach thiis?
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Can't really see enough to tell, at least not without some sort of schematic to let us know what we're seeing.
Better pic
Thanks DanH,
I'm working on a sketch and I opened up the wall some more. I attached a better image. The center beam is three 2x10s nailed together, with one 2x4 hanger nailed to the bottom edge of each side. The floor joists are 2x10s notched to hang on the 2x4s. In the picture you can see the ends of the three 2x10s starting on the right, and one of the 2x4s to the left of that. The ends of the three 2x10s are half rotted away and the half that's left is like powder. I think the beam is not actually transferring any load to the foundation wall. There is a post about 8 feet in. The integrity of the beam just inside the basement seems OK; it takes probing with a screwdriver anyway. The vertical "post" I mentioned before turns out to be a short length of 2x4 that bears no weight.
I'm taking these pictures sitting on the floor of my back foyer, which is built on a pad. The floor sits about 8" above grade and about 24" below the main floor level. That's how I appear to be sitting indoors while I photograph an exterior wall from the exterior side. The foyer is probably not original since it's drywalled. So there's an opening cut into the back wall and a few blocks removed, just to the right of the main beam.
I don't know if this is enough info without a drawing but I'd appreciate any input.
So you're saying that the picture is basically looking in towards the center of the house, with the foundation running left-right in the picture? Is there some sort of pillar in the foundation for the beam, because I see most of a full width of a concrete block before you get to the beam, and if the foundation were running across the width of the picture the beam ends (and the rim joist that is supposedly beyond the foam) would just about be resting on air.
Regardless, it appears that there was at one time some sort of rim joist or blocking in the foreground, as the beam ends have been notched for about a 3" rim joist or some such.
I'm no great expert on rot, but the damage to the wood appears to me to be due to repeated wetting of the wood (and resultant rot), not termite damage.
If this is the center beam, why does there appear to be a break in the foundation (and drywall and a vertical post) to the right?
Pretty much
The picture is looking in towards the house through the rear wall. The remnants of the beam are sitting on the last block before a set of them were removed just to the right of the beam to make way for the rear foyer. The blocks then resume again at the same height for the kitchen. It is possible that the beam was notched for something that has since been removed. The beam runs the full length of the house from back to front and is supported by three posts.
So the foyer is the reason for the break in the foundation, and the drywall and post to the right frames the corner of the opening in the rear wall. Around that corner is the basement stairs.
Based on looking at the rest of the house, the original rim joist is recessed a few inches from the inside edge of the block. There may have been a structural blunder made at the time the foyer was added. Unfortunately, looking at the rotted beam edge it appears that it isn't capable of transferring any load to the foundation wall.
I agree that it looks like rot, not insect damage. Since you say that this is now inside a foyer but presumably was on exterior wall sometime in the past, it is possible that this is old damage the predates the foyer addition and it wasn't found by the person who added the foyer or that person did not want to find it and went ahead any ways. Otherwise, if I understand the location, it would need a prolonged roof leak, flashing leak, plumbing leak or other source of water to cause the damage.