Anyone tries hydrated lime in modern mortar?

[ajneuf]

I started adding a bit more hydrated lime to my mix when working with reclaimed common bricks. It makes the mud so much creamier and helps it stick to the head joints without falling off. I read that some people say the pre mixed bags are fine but I think the extra lime helps with water retention in the summer heat. I wonder if any of you buy the standard Type N or do you have a secret recipe for your mortar?

 

[catiZEN]

I started adding a bit more hydrated lime to my mix when working with reclaimed common bricks. It makes the mud so much creamier and helps it stick to the head joints without falling off. I read that some people say the pre mixed bags are fine but I think the extra lime helps with water retention in the summer heat. I wonder if any of you buy the standard Type N or do you have a secret recipe for your mortar?

Hmm... Adding lime is the only way to go if you want that "fatty" mortar that sticks to the trowel. Modern Type N from the bag can be a bit sandy and short which makes it hard to spread a long bed. A scoop of lime makes it feel like butter and keeps it from drying out before you can get your bricks down. Tried it but not a technique I always use.

 

[z3u$096]

But how about the strength of the wall if you add too much lime to a pre-mixed bag? Those bags are engineered for a specific PSI and changing the ratio might make the mortar too soft for a structural wall. I usually only add extra lime for non-structural veneers or chimney repairs.

 

[the sculpture Arthur]

Have anyone of you noticed that lime-heavy mortar is much easier to clean off the face of the brick? I do some cleaning work too and it doesn't seem to smear as much as the high-cement mixes. It stays together in a clump and lets you flick it off with the trowel without leaving a big grey ghost mark. SO I'd say it's a good technique.

 

[zgeorge]

Oh yes! Lime is a life saver when you are working with old handmade bricks that suck the moisture out of the mud instantly. Without that extra lime the mortar won't bond properly because the brick steals the water before the cement can cure. It gives you that extra minute of "open time" to get your alignment perfect. Used it on quick projects.

 

[speed fighter]

I still prefer the standard mix because it sets up faster and lets me get more courses on the wall in a single day. If the mud is too creamy and slow I notice the weight of the upper courses starts to squeeze the joints out at the bottom of the lead.

 

[Champz]

I usually stick with pre-mixed Type N for consistency, especially on modern work where I want predictable strength. When I’ve worked with older brick or patching, a bit of added hydrated lime does help workability and stickiness but I try not to drift too far from a known mix design so the curing behavior stays predictable.