Two treads and one riser stone in the front steps came loose. What kind of mortar do I need to reset them?
At This Old Spouse they mentioned “a sand-topping mortar mix, which is stronger than regular mortar and can handle wider joints. I mix it with an acrylic fortifier so the joints will be less susceptible to water penetration.” But that was for repairing a stone walkway, not steps.
In our case, one stone has to support the other two, which overhang slightly. Do we need a stronger mortar, and what would it be called?
Janet
Replies
Janet.
If you can post a picture of these steps it might help get you the best answer.
If you're not adept at morter and the steps can "balance" in place fairly well, a urethane bonding caulk (which can be had in light grey) will hold the stone together. You can use blobs or continuous runs of the caulk (held back from finish so it can be struck and tooled or removed after setting). They bond the stone and provide a semi elastic connection.
If you need the morter joint for looks or to bring the treads into proper level, then morter would be my choice. You can use wedges to help hold it at the proper ht. while the morter cures, then plugging the holes if they're visible. Usually the wt of the stone will squeeze out morter and be a pain in the rear for the novice.
Went to Sears to buy sand/topping mortar. Every bag seemed to be solid inside. I lugged a bag (which was surprisingly heavy) to the register and thumped it down onto the counter. "Is it supposed to be this hard?" I asked the clerk. "Is it just packed really firmly--or could it have been exposed to rain?" Sometimes you see pallets of newly delivered merchandise sitting outside the building, and we did have several storms last week.
The clerk poked a finger at the bag. "It must have gotten soaked in the storage area. No, it's not supposed to be like that."
"You had a flood in the last storm?"
"Oh, water gets in every time it rains," he said unconcernedly. Very strange situation for a home-improvement store!
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Right now I don't have the means to post a picture, but I can describe it. The loose tread stones are smaller than the rest because they had to fit around the iron baluster. They may be light enough to so the mortar doesn't squeeze out. Will give it a try. Thank you!
Janet
Be sure to thoroughly wet the surfaces (but no puddles of water) before applying the mortar.
Jyang949,
Don't forget to use a cold chisel to -- very carefully -- chip the old mortar from the underside of your stones if there is some still stuck there. I wouldn't worry too much about the type of mortar or how strong it will be. Just go to Home Depot and buy a box of Mortar Mix. Mix only what you need, maybe even mix it for only one stone at a time. I find that the boxed Mortar Mix at Home Depot sets up really quickly. At any rate, wet your work area -- not sopping wet, just kind of wet then smoosh some mortar, spread it around to a little over the thickness you think you'll need. Carve some grooves in it so the mortar has room to spread a little when you squish the stone on it. I recommend you don't worry about grout joints until the mortar under the stone is set. Just keep the grout joints clear of mortar so that space will be easy to grout the next day.
One more thing -- on some other part of your stairs, measure the vertical distance between treads. Remember that measurement because you don't want to end up with your treads having a vertical distance that's much different. Really try to keep that measurement consistent.
Keep a bucket of clean water and a sponge nearby for clean up purposes.