Forno Bravo Forum: The Wood-Fired Oven Community

Forno Bravo Forum: The Wood-Fired Oven Community (http://www.fornobravo.com/forum/)
-   Tools, Tips and Techniques (http://www.fornobravo.com/forum/f28/)
-   -   Basic nonrefractory brick mortar recipe? (http://www.fornobravo.com/forum/f28/basic-nonrefractory-brick-mortar-recipe-12219.html)

kebwi 03-17-2010 10:45 AM

Basic nonrefractory brick mortar recipe?
 
I need to make a very short brick wall (4" high, basically single "pavers" on their edges). It won't be exposed to heat. What would be the right mortar recipe? I assume it is basically the same as the home-brew but without the fire clay. Something along the lines of 3:1 sand/portland or 3:1:1 sand/portland/lime. I have no idea.

Any ideas?

david s 03-17-2010 01:16 PM

Re: Basic nonrefractory brick mortar recipe?
 
4:1 sand, cement is normal. Usually no lime, it is extremely drying on bare skin. Better to use a squirt of dishwashing detergent to make the mixture more sticky.

kebwi 03-17-2010 01:20 PM

Re: Basic nonrefractory brick mortar recipe?
 
Well, I do all my mortar work with masonry gloves anyway, but if lime isn't usually in the mortar for structural reasons, then no problem. I feel compelled to use this enormous bag of lime I bought. :) My argument for or against lime wouldn't be based on skin exposure, but rather on the correct way to bond bricks. Is lime still not appropriate then? Just 4:1 sand/portland?

Thanks.

Tscarborough 03-17-2010 03:04 PM

Re: Basic nonrefractory brick mortar recipe?
 
1p,1/2l,2-3s is type N mortar. Never,ever put soap in it.

You need thinset for your app.

kebwi 03-17-2010 03:12 PM

Re: Basic nonrefractory brick mortar recipe?
 
May I assume that you recipe is "thinset" then...or were you suggesting I buy premixed labeled thinset despite the inclusion of a recipe in your post?

Sorry for the confusion, just trying to be clear.

cannyfradock 03-17-2010 03:26 PM

Re: Basic nonrefractory brick mortar recipe?
 
Kebwi

Apart from it's thermal properties, lime is only usually added to sand and cement to act as a plasticiser so as the mortar can be more easily applied to walls for rendering/stucco applications.

Normal mortar mix(in any country) as David S said is 4:1. Liquid plasticiser is then added to give it workability. 3:1 would be to strong as the mortar should never be stronger than the masonry that's it's holding together. General principle being that if there's ever movement, the weakness should come in the mortar in a diagonal movement (repairable) as opposed to a vertical fissure which goes through mortar and masonry. Not that this is anything to do with 4" brick pavers laid on edge. As per David s is perfect.

Terry (C.F)

RTflorida 03-17-2010 10:03 PM

Re: Basic nonrefractory brick mortar recipe?
 
Keith,
not being a professional mason, my opinion may not be of much value, but here goes.

Since I am not a mason (no offense, you are not either - we simply like doing our own projects) I have always prefered the ready mix products. Why worry about "what mix is best?" or "did I get the ratios right?" I have done several dozen projects requiring some sort of cement based product - brick, block, wall tile, floor tile, stone, (you get the idea). NEVER have I bothered with mixing my own (except the perlcrete and vermicrete in my oven insulation).
Its always been one of 5 products depending on the application - basic thinset, fortified thinset, premix concrete, Type S mortar, or Type N mortar. Type S or N for all outdoor applications. Not bragging, but I have never had a joint fail or crack in 25 yrs or "projects" (except an arch joint that keeps reoccuring - Heatstop 50), no tile pops, no stone or brick come loose.
For the minimal cost of a bag of Type S or N (maybe $15), why not remove the guesswork?
The premix stuff was meant for guys like us....its not rediculously priced and it REALLY works.

RT

Tscarborough 03-20-2010 08:43 PM

Re: Basic nonrefractory brick mortar recipe?
 
Sorry for the confusion, Kebwi, thinset is your best bet, the formula is the standard for Type N mortar in reference to the post suggesting the use of soap as a plasticizer.

Tscarborough 03-20-2010 09:04 PM

Re: Basic nonrefractory brick mortar recipe?
 
"Normal mortar mix(in any country) as David S said is 4:1. Liquid plasticiser is then added to give it workability."

That is interesting. Do you have any tests and standards as to dosing for the plasticiser? In this part of the world, they are not common or available in DIY quantities.

Here is the relevant standard: ASTM C-270, that is used in the US to determine mortar composition:

How Is Lime Specified Into Mortars?

It can be done either by proportion or by property, using plasticizers would force the mix design to be done by properties.

kebwi 03-20-2010 11:18 PM

Re: Basic nonrefractory brick mortar recipe?
 
I'm a little confused. I realize I'm just making a stupid 4" tall wall so it probably doesn't make any difference at all, but I just want to understand.

It was suggested that I should use thinset to hold the bricks of this dinky wall together and to hold them to the base (the terraces).

First, I'm not sure if thinset is something I make or buy. I know I *can* buy it, but I'm not sure if it is something I can make with the materials already available to me (basic sand, portland I/II (HD's is described as both I and II), masonry lime, (and fireclay but that obviously isn't relevant).

Second, everything I see on line describes thinset as being used to glue tiles to a wall...which what I had always thought thinset was for, that was the only context I had ever heard it in before.

Why would we use thinset to mortar bricks together instead of "brick mortar", whatever that would be? I'm thinking of must just mixing sand and portland about 4:1 and "gluing" the wall together that way (and I guess not including any lime, or I dunno, I had thought, whatever, I don't understand lime at all after this project). Anyway, wouldn't 4:1 work for making a one-level wall? And more importantly, would that not be described as thinset? Would it be something else?

What makes thinset thinset and not brick mortar?


All times are GMT -7. The time now is 07:03 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC