We are interested in strengthening vertical wood timbers in a home that was built in 1894, which are currently experiencing dry rot. The support columns are on cement and appear to be absorbing moisture from the earth below. Any thoughts?
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Could you be a little more specific? What exactly do you mean by vertical wood timbers? And assuming the columns are wood beings the house was built in 1894?
I have a lot of experience with older homes in Elkhart indiana, with a lot of Victorian style homes , with the build-in french doors and the curved stairways and arches and pillars, resembling the same era of building, circa 1900.
That era used a lot of balloon-framing with the lath and plaster (I assume you have the same), now the way you mentioned this ,seems like the timbers (what size and thickness are they?) are resting straight on the concrete.
Is this without a sill-plate or are they perpendicular to the concrete?
If they are rotten very bad, I would temporary shore up the rooms and take out as much of the old timbers out and after that we “sister” more new timbers next to it with 3"galvanized long screws with an impact drill. Also supprt the older timbers again with blocking underneath so there is a double redundant system.The best thing offcourse would be, if you could replace all the timbers on a case by case base! The main issue is this, if and when you put new timbers back on the concrete, you either need 30# asphaltpaper in between the new timber and the concrete and/or use PT (pressure treated) boards, like a new sill-plate ( that I did not hear about yet, sofar), then the next question arises, is this legal in your local area?
Ask the building-department, because in the State of California, they might not allow PT boards to be used inside living-area’s because of their carcigenic character, so be carefull!
Because of this you can either use Cedar and/or Redwood.
Call first!
Either the local building-department and/or the local Architect/Engineer, especially when you work on load-bearing walls!
Hopefully this helps,
Sincerely, Dutchy,Inc.
If a rotted timber is a standalone post or column, the permanent solution is usually to remove it and replace with a new decay-resistant post, isolating the new post from the moisture coming up from the ground. To leave a rotted post in place simply invites moisture to continue to wick up and into the structure of the residence.
Any experienced contractor should be able easily to estimate the scope and cost of the work - some contractors specialize in this type of work. The solution may include new concrete footings below the post or new bracing above. A good contractor will also tell you whether the solution requires the help of an engineer. Good luck, and be safe!
The key to solving dry-rot problems is to eliminate the source of the moisture that’s causing the rot, and to replace any structural elements that have been weakened.
you can also improve the drainage around these vertical timbers… this may not solve the rot that is already there but it would prevent the same thing from happening again should you decide to replace these timbers… at the very least, it would prolong the life of the timbers already in place.