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masonry question
asop
Member Posts: 9,005 ✭✭✭✭
Need a formula for patching roughly 18" long, 2''-3'' high by 2''-3'' deep spots in some OLD exterior concrete walls. Tried store bought stuff but it just ain't what it used to be. Looking for a make up of portland, sand, limestone and water. Thanks
Comments
And I suspect we're going to have the contractor as part of our life for far too long.
What's the coldest temp you can reliably lay brick?
I'm assuming above freezing would be best. But I have no clue.
Or your basic 3-5 shovels washed sand, one shovel Portland, half a shovel of Lime. The colder it gets, where you are, the more sand and lime you want to use. I usually buy pre mix roofing Mortar and add a little Lime for small patches, seal and prime before hand. Sealer dries (tacks) fast, primer (adhesive) can be worked wet.
My stuff never falls off the wall, so I must be doing something right. You want the patch to dry slow, if the surrounding wall sucks the moisture out to fast it weakens the patch bonding. On hot days I whip a little water onto the patch with a big brush to keep it moist as long as practical.
You want your mix to be as thin as practical, just enough stiffness to keep it on the wall. Most people make the mistake of trying to trowel it on like putty (to little water), throw it on the wall and when it stiffens a bit take the excess off. Stucco, plaster, stucco cement, should be the consistency of whipped cream and just stiff enough to hold a peak if you stick a trowel in the bucket then pull it out. It works for me.
No real reason to use cement, Gypsum based exterior stucco will likely work just as well. And will likely hold up better to weather changes that loosen the bond between dissimilar (aged) materials. Seal, bond, stucco.
If you want to spend the big bucks, get some Hydraulic-set mortar and patch with that.
If it is a foundation wall, you can patch it with Type S pre-blend and then seal it with thoro-seal. It's not so much the patching as it is the sealing of the wall.
Patch it with:
http://www.sakrete.com/products/detail.cfm/*_alias/Type-S-Masonry-Mortar
Seal it with:
http://www.chargar.com/Products/*_ma.html
Both available at your local blue or orange store. If you have a masonry supply, go there!
Lime cement works well in very cold climates and/or on structures that move a lot. Those very old houses you sometimes see with the wood framing showing, are plastered in Lime Cement.
If the wall is plastered with lime cement, you want to use lime cement to patch it. Nine sand, 2 lime, 1 cement. If your patch is too hard the wall will flake badly around the hard patch. Masonry expands and contracts with the temperature. Lime cement is relatively soft.
Lime cement works well in very cold climates and/or on structures that move a lot. Those very old houses you sometimes see with the wood framing showing, are plastered in Lime Cement.
Doesn't a pre-blend Type S Mortar cement consist of sand,lime and portland cement, all blended in a controlled environment to ensure a consistent mix for the best strength possible?
I thought lime was used in all cement. Portland,lime and sand?
quote:Originally posted by MudderChuck
If the wall is plastered with lime cement, you want to use lime cement to patch it. Nine sand, 2 lime, 1 cement. If your patch is too hard the wall will flake badly around the hard patch. Masonry expands and contracts with the temperature. Lime cement is relatively soft.
Lime cement works well in very cold climates and/or on structures that move a lot. Those very old houses you sometimes see with the wood framing showing, are plastered in Lime Cement.
Doesn't a pre-blend Type S Mortar cement consist of sand,lime and portland cement, all blended in a controlled environment to ensure a consistent mix for the best strength possible?
I thought lime was used in all cement. Portland,lime and sand?
I'm having a hard time picturing what he wants to patch, I envisioned mostly cosmetic.
Your the expert, all I can do is share what has worked for me. I was thinking he has frost damage. The solution is to exclude as much moisture as possible from the problem area and patch with something that flexes and sticks well. If you patch with something harder than the surrounding material it usually doesn't last long after a few freeze cycles. I did recommend pre mix, we have different materials here, likely the same materials with different names. I recommended generic types, like roofing mortar. Roofing mortar is weather resistant and doesn't need to be painted. A little extra lime is unlikely to hurt anything and may help depending on how hard the base material is. IMO, but like I said your the expert. He did ask about mixing his own and I tired to do a quick explanation about the variables and why.
I was writing while you posted and didn't see your post until after I posted. I wasn't trying to sharp you. Your a mason I'm a welder. But I have done a good bit of brick work, I enjoy it.
quote:Originally posted by pietro75
quote:Originally posted by MudderChuck
If the wall is plastered with lime cement, you want to use lime cement to patch it. Nine sand, 2 lime, 1 cement. If your patch is too hard the wall will flake badly around the hard patch. Masonry expands and contracts with the temperature. Lime cement is relatively soft.
Lime cement works well in very cold climates and/or on structures that move a lot. Those very old houses you sometimes see with the wood framing showing, are plastered in Lime Cement.
Doesn't a pre-blend Type S Mortar cement consist of sand,lime and portland cement, all blended in a controlled environment to ensure a consistent mix for the best strength possible?
I thought lime was used in all cement. Portland,lime and sand?
I'm having a hard time picturing what he wants to patch, I envisioned mostly cosmetic.
Your the expert, all I can do is share what has worked for me. I was thinking he has frost damage. The solution is to exclude as much moisture as possible from the problem area and patch with something that flexes and sticks well. If you patch with something harder than the surrounding material it usually doesn't last long after a few freeze cycles. I did recommend pre mix, we have different materials here, likely the same materials with different names. I recommended generic types, like roofing mortar. Roofing mortar is weather resistant and doesn't need to be painted. A little extra lime is unlikely to hurt anything and may help depending on how hard the base material is. IMO, but like I said your the expert. He did ask about mixing his own and I tired to do a quick explanation about the variables and why.
I was writing while you posted and didn't see your post until after I posted. I wasn't trying to sharp you. Your a mason I'm a welder. But I have done a good bit of brick work, I enjoy it.
Hey, brother GB'r, we are all here to help one another, unless we have wrong motive. I see us working together to help out. No worries on my my end.
Or fill the areas with grout and caulk over the dried grout with Tremco Vulkem. This will be a very waterproof and strong repair.
Sorry, but I can't suggest a solution until I understand the problem.