mortar question

Old 08-09-05, 01:24 PM
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mortar question

This is a problem I have inside my basement, but perhaps people on this thread will be able to help. The mortar joints between the field stones of my 100-year-old basement walls have disintegrated into sand. There is evidence of moisture seepage.

After we have cleaned out as much of the loose sand as possible, what should we do next?

Apply regular mortar? Or a fancy mortar such as Jahn mortar?

Use an acrylic bonding agent?

Use a special moisture sealant? If so, which one?


Old 08-09-05, 01:57 PM
Join Date: Mar 2005
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mortar question

You don't need a special mortar. The surface of you old mortar lasted 100 years and the rest is still doing the job.

I can't address the water seepage without knowing about the structure, gutters and landsacping. You are making a cosmetic repair since the wall is probably far thicker than necessary.

Use a Type N mortar (per ASTM 270). Never heard of Jahn mortar, but he should learn how to spell his name.

Wet the surface to prevent the old mortar from quickly absorbing water out of the new mortar.

You can use a latex bonding agent (Acryl 60 or other). You will end uo buying a 100 year supply (probably 1 quart).

Apply with a mortar bag (like a big cake decorator).

Smooth ot tool the joints depending on the size and depth.

This should make it similar to what was built 100 years ago. Now you can go and fix some 500 to 1000 year old masonry structures.

Old 08-12-05, 08:52 PM
The Tuckpointer
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Jahn mortar is for patching different types of stone such as sandstone, limestone etc. The mortar you need you can buy at Lowes or Menards. A type N mortar will be a good mortar to use for your project.

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