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22

My only guess is that a watery mix will have the layers settle in their different sedimentary layers with the fine cement settling to the bottom... One reason is that the aggregate can settle to the bottom much too easily, yes. This is called segregation and results in non-cohesiveness of concrete. Another reason too much water is bad is that it can ...


14

It certainly is acceptable to do a tile job in phases. There's no structural reason that tiles need to have their supporting mortar connected mechanically. The critical bond is to the substrate, not adjacent tiles or mortar. Large residential and commercial tile jobs are done in stages every day, and with no special procedures or materials. One caveat ...


13

Hacksaw? If you saw thru the rusty plate (twice, one for left slot and one for right) and remove it by pulling it out from under the screw, the remaining screw will be sticking up enough for you to get hold of the whole head with a pliers and unscrew it. It is hard to argue w Alaska Man (or you) re merits of replacing the whole box. But it seems like you ...


12

It's all about particle size, which is classified using the Wentworth scale or The Krumbein phi (φ) scale. Sharp Sand Sharp Sand, also known as Concrete Sand is a coarse sand with larger particles. This type of sand is typically used in concrete. φ scale - 1 to 0 Size range - 1/2 to 1 mm (0.020–0.039 in) Builder's Sand Builder's Sand, also known as ...


11

The white powdery substance is called efflorescence. It's bascially mineral salts leaching out of the masonry. The efflorescence itself may not be anything more than a cosmetic problem, however the appearance of efflorescence indicates that there's moisture present in the masonry. This is not entirely surprising--you're talking about an old brick wall ...


11

If you have a pulley and no way to anchor it overhead, you could always lift from the top, with the pulley attached to the bucket. Of course, you'll need to have an anchor for the rope somewhere on the floor you're at, but it only has to be at the height you want to lift the bucket to. The resulting load will be half of the bucket that you're lifting. If ...


9

The reason is because of the hydration chemistry that takes place in the cement while it cures. When cement cures, it doesn't really "dry", the way a towel dries, but instead it reacts, the water ceases to be water and merges with the substances in the cement to form new molecules. Having too much will disturb the chemical interactions taking place and will ...


8

WD-40 is NOT a good penetrating oil. Liquid Wrench is better, but still not that great. The best kinds are called Kroil or PB Blaster, you can find them in auto parts stores. But if you don't have an auto parts store nearby, wintergreen oil can be bought at many drug stores and is much much better than WD-40 or Liquid Wrench. With a good penetrating oil you ...


7

Mortar is not waterproof. However, there are products that can be applied to mortar (and other concrete materials), that can make the mortar waterproof.


7

you can certainly stop for the day. the things you have to watch are: a) finish your tiles all in one line or row, not on the diagonal. that way you can check it with a laser or string to make sure everything is straight. once it sets, you can't nudge tiles to get a good line. b) depending on your pattern, you may have adjacent joints lap one, two, ...


6

I have been a practicing stone mason for fourty years and I have seen the long term affect of the 1:3 mix compared to the 1:2 mix. With proper preparation from the base under the footing and throughout the build, I recommend the 1:2 mix particularly with flagstone and surfaces that are going to experience a lot of weather. My experience is almost ...


5

In my years in the construction trade, here is my synopsis of concrete floats and trowels and their uses. I will start with the screed. A screed can be as simple as a short piece of framing, 1X3 or 2X4, long enough to go from side to side of a concrete form, whether it be for a 12" thick foundation or a 3' wide side walk. For larger poured slabs the screed ...


5

Next time, tamp the cement into the corners (using a putty knife, large screwdriver, gloved finger, etc.) after a couple inches is set down. If you wait until the form is almost full, it forms stronger bubbles and they are harder to coax out. Structurally, the curb is more than strong enough unless you anticipate automobiles driving over it. The major ...


5

Considering how little exposure you will get to the mortar for your small project, you're probably fine with just your work gloves. Wearing latex gloves under your work gloves will provide additional protection. I would suggest that for the people who will be working directly with the mortar. Big picture, more important than gloves is breathing protection. ...


5

Lift the dry materials, run a hose for the water, mix in place, avoid having to lift the weight of the water. The REALLY EASY but rather expensive method - hire a concrete pump truck for the day.


5

I had a project some years back building a 28 foot high chimney. Needless to say there was a need to hoist a lot of buckets of mortar and then all the chimney blocks and flue liners up to the work site. I ended up renting some scaffold bracket assemblies that came with a overhanging cross bar with a large pulley hanging on the end of it. You could try this ...


5

Try using an impact driver , the other rusted screw may shear off though , judging by its condition. I'd opt replacing the box , as its too much headache to fix. If you do get it out, try adding antiseize next time to the screws or getting a box that has a better design regarding screw placement and water entry (ip rated waterproof/outdoor gpo?) or even ...


5

Cut strip in middle. Bend each part and use as a "spanner" to friction turn the screws while also applying torque to the screws. Having three arms or a helper makes this easier. Once you have even slight screw movement a vice-grip can grip the heads. Filing flats on opposite sides of a screw head make it much easier to grip them with a vice-grip, ...


4

Figure 5 shows the effect of porosity caused by excess water. http://matse1.matse.illinois.edu/concrete/prin.html I recommend reading the entire article. "The strength of concrete is very much dependent upon the hydration reaction just discussed. Water plays a critical role, particularly the amount used. The strength of concrete increases when less ...


4

It depends on the concrete permeability and the tile permeability (is it porcelain (essentially zero permeability) or a ceramic bisque (most non-porcelain tiles))? A sealed concrete floor and a porcelain tile will greatly extend the cure cycle by limiting moisture migration. It is for this reason that Schluter (a tile membrane manufacturer) specifies a ...


4

Since you're working with other minors, at a very minimum, you should follow OSHA guidelines: Skin Irritation: Wet portland cement can cause caustic burns, sometimes referred to as cement burns. Cement burns may result in blisters, dead or hardened skin, or black or green skin. In severe cases, these burns may extend to the bone and cause disfiguring scars ...


4

Yes, mortar is waterproof. It is "relatively unaffected" by water "under specified conditions". Water-proof or water-resistant describes objects relatively unaffected by water or resisting the ingress of water under specified conditions. –Waterproofing, Wiki However, anything claiming waterproof is likely a long way away from being watertight or ...


4

Probably not a good idea. As you said, the stones are heavy. If you could guarantee a solid rest on the floor, maybe, but I'd simply cut out the drywall a few inches inside your stone area, replace it with 1/2" cementboard, and call it good. This would be simpler than the wire lath business. I'd float backing at the joint of the cementboard and drywall to ...


4

Contact of the bottom of a steel tub with a mortar bed could cause corrosion of the tub from the bottom. If the instructions do not call for a mortar bed, I would not use it without expert opinion to the effect that it is a benefit. A good quality steel tub does not need the support of a mortar bed.


4

Tile mortar is actually fairly soft. If you have access to a belt sander, take a coarse grit to it. Otherwise, scrape at it with a robust flat tool like a cold chisel.


4

Tapconing into a mortar joint is to be avoided. See the discussion here. And the one here about how 3/16" are garbage. Use 1/4". If the Tapcon goes into a mortar joint it's pull out strength will depend on the compressive PSI of the mortar and the depth of the mortar joint in combination with the length & diameter of the Tapcon. – forums....


4

For something as substantial as a mantle, I would not use simple Tapcons. Tapcons are great for simple fasteners, but aren't that great for something like this. I would highly suggest installing a sleeve anchor of some sort. You'll get better traction on the brick/mortar and it will penetrate the surface easily. If you're absolutely set on using Tapcons, I ...


4

I would suggest re-doing the cement for the bricks, allow to dry. Then once hard I would secure a wood panel (12" or 15" square) over that area to help hold the bricks back. Then drill gently.


4

The box looks like it is plastic, so if you can get a good grip on the screws, they should be able to be forcibly removed. You could start with the impact driver, then the ole Dremel a deep slot in the top, and if that fails, I like Willk's suggestion of hacking (or cutting) out the crossbar to get more access to the screw head. A vice grips should work ...


3

One of the measures used when specifying concrete is the water to cement ratio. If there is too much water, the chemical reaction (hydration) that "cures" the cement in the concrete is adversely affected if there is too much (or too little water) in the mix, leading to weaker concrete than if the optimum amount of water is used. Concrete companies measure ...


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