The mortar should be thick enough to stick to the trowel when you turn it upside down. If it drips off then it's too thin, and you need to add more powder to the mix.
You see, when thin-set mortar is incorrectly applied, the installation will many times fail. More likely than not, the tile will break - as you see in the image below. Not a good situation for the customer and a terrible one for everyone involved in installing tile correctly.
The terms thinset cement, thinset mortar, dryset mortar, and drybond mortar are synonymous. This type of cement is designed to adhere well in a thin layer – typically not greater than 3/16th thick. For example, a 3/8″ notch trowel will produce a 3/16th inch thick coating after the tiles are pressed in to the cement.
If it's a little runny, it will still work. If it's a little thicker, it can still work as well.
The minimum mortar thickness, after embedding, for conventional thin set mortars is 3/32” with the maximum thickness being 1/4” (depending on the mortar manufacturer's recommendations).
A mixture that is just right should be smooth and consistent – not dry or crumbly. If your mixture looks too runny and watery, or the ridges collapse very quickly, there's too much water in there. Try adding more dry ingredients to solidify your mix.
While thin-set mortars have been popular and effective for standard tile and stone installations for many years now, a thin-set mortar bed is just 3/32" to 3/16" thick and as we get beyond the 12" x 12" format, sub-floors need to be absolutely flat for standard thin-set mortars to be used on these large tiles.
Mortar that is too wet will run out between the joints.
While thinset is technically a modified mortar, it's thinner and designed specifically for tiles, unlike mortar which is thick and holds stacked bricks in place. Likewise, thinset contains cement, but its formula lacks the strength to build walls or even serve as a stand-alone flooring product.
First, you must know how much thinset mortar you want beneath the tile in the finished installation. A finished installation requires a minimum of 3/32” beneath the finished installation, aiming for a 1/8” minimum makes it easier to calculate the proper tile trowel size.
Rotafix Under Water Mortar is a polymer modified cementitious mortar that is capable of curing under water. Rotafix Under Water Mortar powder is a blend of special cement powders, high quality graded sand, and a unique combination of polymers and admixtures.
Add the mortar to the water, mix, add more mortar or water as needed to reach a fairly thick consistency – about the creaminess of thick peanut butter.
Repairing damaged mortar is a process that begins with first removing every trace of cracked, flaking, falling and decaying mortar from the gaps between the brickwork. The remaining mortar and surrounding structure must then be carefully cleaned, after which new mortar can be pressed into place and left to cure.
If you let grout or thinset dry out as they are trying to harden, they simply won't harden very well, and then they will be crumbly and not adhere well to surfaces. I don't ever tile with mortar in direct sunlight if I can help it and will rig tarps if needed to minimize the effects of sun and wind.
Both grout and mortar are essential materials for tile installation, but they serve different purposes. People tend to get them confused, or even think that they're the same thing. Thinset mortar is used to adhere tiles to a surface, while grout is designed to fill the spaces between tiles once they've been installed.
With a non-slumping formula to eliminate lippage, Medium Bed Mortar can be applied to 3/4" (19 mm) thick on horizontal applications. Use it for vitreous, semi-vitreous and absorptive tile, including ceramic, quarry, pavers, cement and porcelain, gauged or ungauged natural stone and pre-cast terrazzo.
In short, bricks and mortar aren't 100% waterproof.
On the other hand, if you add too much mortar mix, then the mortar might easily crack or shrink. Cracking can cause many problems for you in the long run. The best consistency of mortar for bricklaying is for it to be wet and thin.
Brick mortar is made from Portland cement and is used for more structural and load bearing projects. It will reach 60% of its strength within the first 24 hours and will take up to 28 days to reach its full cure strength. There are 5 types of brick mortar, and all cure differently than each other.
Start with a visual inspection of the brick joints.
Look for signs of failing or missing mortar joints between the bricks. You may need to follow up by performing a probing test with a small knife. If the mortar is loose, crumbling, or falls out easily with digging, it is in need of repair or restoration.
As we said above, in most cases the best option is to have a bed joint that is 10mm thick. If you had joints that were 6-9mm thicker, they could have as much as 30% less compressive strength. The thicker joints can also be a big waste of mortar. You'll be using far more than necessary on every single joint.
The only thicknesses that the tile industry requires is that the mortar under your set tile be a minimum of 3/32nds of an inch thick and no thicker than the maximum specified by the mortar manufacturer. For most standard thinset mortars that's 1/4 inch. My opinion; worth price charged.
Masonry blocks
Note: The standard thickness of a mortar joint is 10mm.