Any Brick Masons here? Questions about repointing bricks on 1918 home...Cement/Lime/Sand Ratios???

[masmdu]

I have found out that I have to be careful not to damage my bricks in my foundation by making sure that I have the proper mortar mix...


I need to figure out the ratio of the mix of cement/lime/sand...

Any help would be terrific...Thanks!

[TwilightGardener]

1. I used this site and its forums for my old house--

http://www.oldhouseweb.com/how-to-advice/repointing-mortar-joints-in-historic-masonry-buildings-part-i.shtml

[nebenaube]

2. that's correct...

At least I know I've heard that mentioned during historic renovations here in Wisconsin. Otherwise, the new mortar expands/contracts at a different rate from the original. My suggestion is to go to a used book store and find a mason's/construction manual from that time period.

[sandnsea]

3. Donors can access a DIY forum

And you can donate as little as $1 to get a donor store. Lots of great info in there and people who might see your question who won't see it here.

On edit:

Anybody can access the forum, donors can post in it.

http://www.democraticunderground.com/discuss/duboard.php?az=show_topics&forum=287

[M155Y_A1CH]

4. Here's what I know

if the bricks were made without any portland cement in them you can't use any cement in your mortar. The faces of the bricks will pop off in freezing weather.

If you have a chunk of old mortar, drop it in a cement slab and if it clinks - it has cement in it, if it thuds - it does not. If they originally used cement it is safe to say the bricks also contain it. Cement free brick can be scratched on it's face with your fingernail and harder, more modern brick cannot.

If, indeed you have the old soft brick use NO portland cement.
For small jobs you can buy lime putty in buckets and mix with damp sand up to 6 parts sand to 1 part lime putty. For big structural repairs you would use type S hydrated lime,sand and water. (note: not Type S mortar and not hydraulic cement)

If you clink and can't be scratched you may use off the shelf mortar mixes. Look for one with a long working time for pointing repairs.

[old mark]

5. Not quite on topic, but old bricks that can be scratched

should never be powerwashed - it cleans off the hardened surface and exposes the softer inside to damage.

My house if from 1920 or earlier, too.

mark

[M155Y_A1CH]

6. Absolutely true

Handle them with care.