Replies

1. 
   DanH | Mar 18, 2013 07:34am | #1

   Those are tiles, not bricks -- quite light.  And obviously the mortar is pretty sticky.

1. 
   mbole | Mar 18, 2013 06:50pm | #3

   Those are tiles, not bricks

   Tiles on first video, but bricks on the second (or my english is bad :))

1. 
   DanH | Mar 18, 2013 07:28pm | #5

   You notice in that second clip he's working really fast.  And the structure is cleverly designed that as the bricks get more and more horizontal the distance between ends that must be filled to complete the arch gets smaller and smaller.  So the mortar only needs to be stiff enough to support the bricks for a few minutes.

   It's been about 20 years since I was last in Mexico, but I recall that they were fond of using mortar with a very high cement content.  Don't know if this has anything to do with things.

2. 
   florida | Mar 18, 2013 09:15am | #2

   These are arches that press outward on each end. The mortar is very sticky and will hold the bricks in place until it dries. It's a traditional Mexican method of constructing roofs when wood is not available. If you have access to back issues of FH there was an article explaining the technique about 20 years ago.

1. 
   mbole | Mar 18, 2013 06:55pm | #4

   These are arches that press

   Of course, I understand how it stands after entire arch is completed.

   Problem is before completition of the arch. When you lay brick on almost vertical surface and it dont fall off.

   What kind of mortar is used? Never seen something like this before.

   Unfortunatly I dont have back isuses.

3. 
   tomask | Mar 19, 2013 08:17am | #6

   Plaster

   My spanish isn't great, but in the comments of the first video, he describes the mortar as a commercial product made of semi-hydrated calcium sulfate, ie. gypsum or plaster of paris, similar to what we use for wall plaster or joint compound here in the US. It's very fast setting, but not very structurally strong. One minor earthquake, and......

1. 
   tomask | Mar 19, 2013 11:06am | #7

   Second video

   In the second video, it looks like hes using 4 parts sand (river, mine, or sea), 2 parts lime, and 1 part gray cement (Portland, I assume).