I have a 2-story home on Long Island, New York, that was constructed on a slab.
While doing some remodeling, I discovered that the slab was poured in sections that were divided by 2X4 studs laying horizontally and directly on top of the soil (on top of a thin flashing barrier). Plate studs were then nailed to these bottom studs and then the walls were constructed on top of these. The house is about 30 years old.
Termites have turned the bottom studs to powder, causing settling. I am particularly concerned about two 6-foot door openings off of the center foyer, that are topped by 2X12 headers.
I have torn out the termite-damaged wood and I am now left with sections of slab divided by 4-inch wide, 4-inch deep troughs that are 8-feet long. I do not want to replace the damaged wood with more doug fir 2X4’s, and I don’t think pressure treated wood is a good idea on the interior of the house.
I would like to fill the trough with cement and place a steel column on either side of each doorway to support the headers. My thinking is to dig down as deep as possible and also sideways under the slabs as far as possible, so as to create mushroom-like pads to support the steel columns.
I have spoken to several carpenters, etc and keep getting different opinions ranging from no digging (“just pour the cement into the trough”) – to chopping up the slabs and digging a 48 inch footing 18 inches around to support each column (I think that is a bit extreme!).
Any wisdom or advice you can offer me would be greatly appreciated!
Thanks,
RICO
Replies
I don't see a problem with using PT lumber in this situation but I might prefer to lay into the channel occasional sections of steel channel to support your bottom plate.
If your returning the wall to it's original frame and load I wouldn't do more than what was there at the headers. The reason being the load issues are along the walls length not totally at load points by the doors. If your removing the walls to a spanned opening between doorways then consideration of a footing would be in order on either side of the headers.
Unless the troughs were below your exterior grade or stressed fractured to the soil below, your termites accessed as any would. Nothing special to the troughs. And if so your termite damaged may be more extensive then you think.
This trough might be a perfect place to drill and saturate for the little buddies.
This hurts a little, seeing the little guys eliminated.
Termites have been very good to me. If God hadn't invented termites a carpenter would have. I've often thought if it were possible to propagate termites in affluent neighborhoods, for future work.
rico.. i agree with jagwah.. i see no problem with the PT in the interior.. it doesn't outgas...
it doesn't represent a threat to the inhabitants by being buried in your slab anymore than it does being used as a mud-sill on the millions of other houses in the USMike Smith Rhode Island : Design / Build / Repair / Restore
Thanks for the advice! I've got the exterminator coming next week. I'll be checking out other sections of the house a bit at a time to look for other damage and dealing with it as it comes.
So you would use PT rather than cement? Could you please elaborate on the steel channel idea?
Thanks again.
Rico
With any luck there's a steel channel that will lay in the trough high enough to be level with the slab, your 4". Rather than laying a continous channel in the trough I'd cut 16" sections and space them under the plate for bearing.
Actually I'd probably just lay PT lumber back into the trench. I don't know if I'd fill it with concrete due to possible movement of the slab. This trough surely has acted as a stress relief for the slab and cracked in the bottom,I assume.
I must say it has got me to ponder the curious way that they did your slab. I'm still working on that one.
hey rico- where are you located on the island??......