Does Anyone Know About Surface Bonding Cement

Rolacoy

I am trying to get information about Surface Bonding Cement. I have been told that it is possible to stack cement blocks with no mortar in between the blocks and trowel on this cement to build walls.

concretemasonry

Yes, it is possible. Both sides of the block must be coated according to the instructions given surface bonding cement manufacturer. Ordinary cement or mortar will not work.

The wall is weaker for vertical load than conventional.

The biggest difficulty is to be able to stack block vertically. If you are to build something like a garage and have never laid block with mortar, you could probably learn how to use mortar and lay all the block the conventioanal way as fast or faster than using surface bonding.

You should check out to see if surface bonding is permitted where you are.

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Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

Rolacoy

I was once told that masonry cement was not used to hold blocks together, but to hold them apart. That if they were dry-stacked they would crack. That makes some sense. I have laid quit a bit of rock, some brick and block.

The garage is 33' x 24' x 10' tall. I plan to use cultured stone on the front of the garage and a stucco finish on the rest. It seems like surface bonding cement would work very well. Where I am putting the stone, I would just bond it into the cement as I went.

concretemasonry

Do not use masonry cement, mortar cement or any home-made mixture.

Surface bonding materials must contain fibers for reinforcement and it must be applied at the proper thicknes.

The original surface bonding paroducts were made using normal glass fibers that were eaten by the cement since they were alkalai reisitant. Later versions used special alkalai resistant fibers or man-made fibers that are selected for use with cement. The proportions are very critical. - This is the reason you should not use anything that is approved. The code is there to protect you.

Cement is not used by itself is masonry. Mortar is!!! - You are right that MORTAR both hold block yogether and keeps them apart.

The reason a surface bonded or any dry stacked wall is weaker in compression than a normal block wall is that there is no mortar between the block to spread the load perfectly uniform.

Some surface bonding material contain a waterproofing material, so the surface might have to be quite rough to get a good bond.

__________________
Dick

Engineer, designer and consultant recently active domestically and internationally on construction and design in about 35 countries.

Tscarborough

I have done many small surface bonded projects (kids playhouse, planters, etc.), but I would only consider using surface bonded walls if they were also engineered to be under compression. Besides the technical questions, it is not that much cheaper, and certainly not better than laid units.