Bricks, Masonry, Asphalt and Concrete - Mortar Mix alphabet soup
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AlexH
08-01-05, 01:39 PM
Hi,
I'm starting a couple of projects and I would like to make sure I'm choosing the best mortar for the various applications -
First project is walkway with brick edging and flagstones (in mortar of course). Already poured concrete base about 3" below grade. Bricks will need about 1 to 1.5" of mortar under them. Flagstones will be similar but I need to avoid lime due to discoloration. Can I use a 1:4 mix (no lime) of Portland - sand for this whole job - brick base, flagstone base and grout for both? I don't really need workability for horizontal surfaces, do I? This way I could avoid any chance of discoloration although I don't know how serious of a problem this really is.
Second project is 16" high planter made from concrete block, capped with brick and flagstone veneer. Proper footing is already in place. I was already told to make block wall with N-type mortar. It is difficult to place the veneer flagstone with a 1:4 Portland-sand mix (no lime)? The flagstone is not gauged but I can probably select for pieces of 1" thickness or less.
By the way, I would like the block wall to have a slight radius on the front (on the order 10' radius). Is this OK since it's not structural?
Thanks
I'm starting a couple of projects and I would like to make sure I'm choosing the best mortar for the various applications -
First project is walkway with brick edging and flagstones (in mortar of course). Already poured concrete base about 3" below grade. Bricks will need about 1 to 1.5" of mortar under them. Flagstones will be similar but I need to avoid lime due to discoloration. Can I use a 1:4 mix (no lime) of Portland - sand for this whole job - brick base, flagstone base and grout for both? I don't really need workability for horizontal surfaces, do I? This way I could avoid any chance of discoloration although I don't know how serious of a problem this really is.
Second project is 16" high planter made from concrete block, capped with brick and flagstone veneer. Proper footing is already in place. I was already told to make block wall with N-type mortar. It is difficult to place the veneer flagstone with a 1:4 Portland-sand mix (no lime)? The flagstone is not gauged but I can probably select for pieces of 1" thickness or less.
By the way, I would like the block wall to have a slight radius on the front (on the order 10' radius). Is this OK since it's not structural?
Thanks
Concretemasonry
08-01-05, 02:17 PM
You seem to have your preferences for mortar made based on the avoidance of lime.
There is no problem making a curved wall by holding the inside joint tight and opening up the joint on the outside face. From an aesthetic standpoint, one of the head joints will be out of size, you can choose which it is during your layout. - Just lay out and dry fit the first course. This method is structurally satisfactory.
The thinner the block, the tighter radius you can build. There is no problem using 6" block, so you can get to a 10' radius easier. With an 8", it gets tough on a 10' radius.
Regarding lime, if you used a pre-blended Type N mortar, you probably didn't get any lime in it anyway. Most pre-proportioned masonry mortars are a mixture of portland cement and a filler like ground limestone and additives (soap, spit ?, etc.) to give it more workability. It works OK, but does not have some of the long term benefits that lime provides.
In general - use the weakest mortar you can. Strong mortars (Types M & S)not not the best for some uses. Mortar has a minimal effect on the compressive strength of a wall.
Dick
There is no problem making a curved wall by holding the inside joint tight and opening up the joint on the outside face. From an aesthetic standpoint, one of the head joints will be out of size, you can choose which it is during your layout. - Just lay out and dry fit the first course. This method is structurally satisfactory.
The thinner the block, the tighter radius you can build. There is no problem using 6" block, so you can get to a 10' radius easier. With an 8", it gets tough on a 10' radius.
Regarding lime, if you used a pre-blended Type N mortar, you probably didn't get any lime in it anyway. Most pre-proportioned masonry mortars are a mixture of portland cement and a filler like ground limestone and additives (soap, spit ?, etc.) to give it more workability. It works OK, but does not have some of the long term benefits that lime provides.
In general - use the weakest mortar you can. Strong mortars (Types M & S)not not the best for some uses. Mortar has a minimal effect on the compressive strength of a wall.
Dick