Concrete and Cement

Buildings today cannot go without concrete and cement. Cement mixed with water, reinforcing steel, sand and gravel, binds all of these components together. When dried, it becomes hard as a rock, which is perfect for buildings and infrastructure.

4,816 Questions
Home Improvement
Concrete and Cement

Can you install a toilet on a four-inch cast in a basement floor?

Yes, you can put a toilet on it. The hardest part would be putting a toilet flange onto the cast. There are two options: you can either get a cast iron flange to fit over it and pour a lead joint or you have to chip around the pipe enough to get a no hub band on it. You also have to consider the distance from the wall. If it's 15" to the back wall you only need a minimum of 12" to finished wall. That means if you fur the wall out you could only fur it out 2.5" leaving you with 1/2" drywall. The side of your toilet needs a minimum of 15".Here is more input from others:* Go to your plumbing or hardware store. There you'll find a brass flange you can fasten to the floor with zamma pins. You will not need to chisel the floor with this method, but, you will need ensure the 4" is flush to the floor. A hammer drill is also needed to drill six 1/4" holes in the cement for the zamma pins.* In order to ensure the proper safe and sanitary conditions of your plumbing system it is recommended that you hire a licensed plumber to do this type of work. If the floor of your basement is concrete it will have to be jackhammered to expose the cast iron pipe under the floor. The pipe will have to be cut using proper tools. Cast iron pipes are hard and brittle at the same time and if they are old and corroded will often crack. A proper fitting will have to be installed and fastened with right couplings to be water tight. Plastic ABS 4" pipe is then installed vertically though the floor just above the floor level and proper distance from the wall in back of the toilet, capped and wrapped to accommodate the floor flange after the concrete is poured back. When the concrete dries the cap and wrapping are removed, the ABS pipe is cut flush with the floor and toilet floor flange is installed.* You may be able to add a toilet to the line but it must be properly vented!*Another option, and probably the easiest for a homeowner, is to buy what is called a "twist and set flange". It is basically a PVC flange with a longer base that has 2 rubber seals that actually thread into the cast iron pipe. You would insert the base of the flange into the pipe and turn it until it becomes firm, then I would suggest anchoring it to the floor with 1/4" drive pins, or some other form of anchor.

Swimming Pools
Pool Building and Repair
Concrete and Cement

For concrete deck material is Kool Deck or an acrylic considered superior?

As with all design choices, the answer is it depends on what you are trying to achieve. First, let's start with a few basics on understanding the comparison. A genuine Kool Deck brand surface from Mortex Mfg. is a pure cementitious topping unlike an "acrylic", which is a polymer modified cement. A Kool Deck surface will undoubtedly have a lower relative surface temperature than an equivalent acrylic topping of the similar color and will also be more skid-resistant when either wet or dry. A polymer modified cement topping will generally have much better stain resistance than a Kool Deck surface (which can be enhanced to provide similar stain resistance at a cost). Polymer toppings for the most part are deemed easier to apply and require less people for a job. This simplicity does come at a price, as the cost of materials is significantly higher than all the materials required for a Kool Deck surface. The major hurdle for those looking for Kool Deck surface is finding a skilled applicator to insure a proper application - look at the work of the contractor and do your homework!

Bottom line is that a Kool Deck surface is still the best choice for barefoot areas where comfort is king, while polymers are better suited for deck areas expecting staining problems, customer wants custom patterns, or applicators are more comfortable installing the latter.

Sun Deck is an acrylic concrete deck finish that is very durable, stain resistant, and cool. Also quite popular in South Texas.

Acids and Bases
Concrete and Cement

How do you use muriatic acid to etch concrete?

For anyone interested in the TRUE HCl concentration of muriatic acid (sans WIKIfication) simply google "muriatic acid msds" and you will see that, while the concentration varies by manufacturer, it generally ranges from 33-40%. Furthermore, even if you order HCl by name from a chemical supply house, you order by concentration, usually some reagent grade, with fuming HCl starting at ~40%. No hardware store in the world sells 100% HCl for etching concrete.

DANGER / SEVERE HAZARD -- Muriatic Acid IS UNDILUTED (100% concentration) Hydrochloric acid.

Wear Eye and face protection, acid resistant gloves, rubber slicker suit, or be VERY careful as Hydrochloric acid is highly corrosive and can instantly burn holes in your skin and tissues, and right through all woven clothing.

When diluting ANY acids, it extremely important that you NEVER ADD WATER TO ACID, as the reaction between the two will result in an "explosion" throwing acid instantly in all directions.

The PROPER method of diluting acids is to very SLOWLY pour the concentrated acid into a larger volume of water.

For an additonal "layer" of safety, do not pour the acid from a large and heavy container, as it is more difficult to handle and control. Pour the needed amount of concentrated acid into a smaller, acid resistant, container which will be easier to handle and therefore control the pour rate.

When using baking soda for neutralizing acid residues, be VERY CAREFUL to NOT ALLOW the baking soda to contact the UNDILUTED ACID as the resulting reaction can be explosive!

1Bust out some protective clothing and a gas mask. Have a good supply of fresh water on hand in case you need to rinse any body parts.

Be very careful with muriatic acid; it's 30% hydrochloric acid, and is fairly hazardous.

If you only want to barely 'etch' a slippery concrete surface, it is best to dilute the acid with water, as acid straight from the bottle tends to be very aggressive with any concrete surface, and can badly damage the surface very quickly.

For a deeper etch Pour the substance where you want to etch the concrete and spread it out with a nylon broom. let it sit for a half-hour. Wash it thoroughly with the hose after.

I have used a small hand held spray bottle set to a fine misty spray, and skipped the 'rinse' step altogether with very good results.

'Baking Soda / water solution' is an acid neutralizer, and can be used around most landscape with safe results.

>>> Get used to the process FIRST. Buy a few cement blocks, bricks, or slabs that you can throw away. Different concrete blends, strengths,... react differently. New and old concrete of the same formula will also react differently. An new slab poured next to the exact same mix from the same company in an old slab will be different due to moisture content and curing time).

Good luck.


#3, You follow the MFG directions on the product as with anything.

You use Ammonia to neutralize.

Concrete and Cement

How many yards of concrete will cover 500 square feet at 4 inches thick?

a 'yard' of concrete means 1 cubic yard volume (1 yd * 1 yd * 1 yd).

This is 3 ft * 3 ft * 3 ft = 27 ft3

4 in = (1/3) ft

Your coverage of 500 ft2 * 4 in = 500 ft2 * (1/3) ft = (500/3) ft3 166.6667 ft3

so (166.66667 ft3 ) / ( 27 ft3 ) = 6.1728395 yards of concrete

Answerthats way too difficult for my simple brain try this

sq' x 0.0031 x # of inches

500 sq' x 0.0031 x 4= 6.2 yards

Okay lets make it simple .... I dont even understand there answer . Okay... multiply your length and width so lets just say 10' x 50' = 500 sq ft then take 500 and then divide it by 81 (81 is 81 sq ft witch is a yard of concrete at 4 inches) = 6.1728395 so if ordering concrete you'll need 6.25 yards to complete your project.

Lawn Care
Weight and Mass
Concrete and Cement

How much does a yard of gravel cost?

Most coin size or smaller gravel runs about $20-25 a yard (ton). That will usually cover about 100 sq. feet at 3 inches deep.

Painting and Staining
Concrete and Cement

Can you paint concrete with wood stain?

No. It will definitely leave a "stain", if you will, but it will come off with use. A specially formulated compound must be used that bonds with the concrete. See your local Home Depot or Lowes. It's not cheap.

Civil Engineering
Concrete and Cement

Can you fix an asphalt pothole with concrete?

They have different modulus of elasticity. This would cause ces in thermal expansion and therefore fracturing of both materials.

Home Improvement
Concrete and Cement

Can you install hardwood flooring over laminate?

No, laminate is floating type of floor installed over an insulation pad.

Hardwood floor has to be nailed, stapled or glued to the subfloor.

If you do manage to install hardwood on top of laminate sooner or later your Laminate floor will expand due to high temperature or humidity and it will create gaps between hardwood planks.

Math and Arithmetic
Concrete and Cement

How many square feet will a yard of concrete cover at 4 inches thick?

Assuming you are talking about a cubic yard of concrete then this will cover 81 square feet to a depth of 4 inches. This is how you work it out. A yard is 3 feet. so a square yard (3 feet by 3 feet) is 9 square feet. There are also 12 inches in a foot and 3 feet in a yard, which makes the cubic yard of concrete 36 inches high.

Thus imagine you take your cubic yard of concrete and place it down once and saw of 4 inches from the base this will leave square 3 feet by 3 feet square feet of concrete with a depth of 4 inches when you lift the top bit off.

So you need to know how many times you can place it down and cut off 4 inches. As the block is 36 inches high and 4 goes into 36 nine times this means you can cut the block into 9, 4 inch thick, 3 foot by 3 foot square slabs, which is the same as 81 square feet.

Concrete and Cement

What does precast mean?

A structural members especially of concrete; cast into form before being transported to the site of installation.

Civil Engineering
Bridges and Tunnels
Concrete and Cement

What is the concrete mixing ratio in m25 concrete?

The mixes of grades M5 M10, M15, M20 and M25 correspond approximately to the mix proportions (1:4:8), (1:3:6), (1:2:4), (1:1.5:3) and (1:1:2) respectively.

Concrete and Cement

How do you cover brick with concrete?


Civil Engineering
Bridges and Tunnels
Concrete and Cement

What do you mean by M20 concrete?

In this M refer to Maximum compressive strength and 20 refer that concrete that with stand upto 20KN compressive strength.

Painting and Staining
Concrete and Cement

How do you clean stains on concrete?

OK, that is stamped concrete. things you don't want to use are a pressure washer. It will blow the release color off the concrete and destroy the area you are trying to save. first you will want to remove any sealer on the the affected area, you can do this with xylene (you can get it right at home depot) this won't hurt the concrete or the color, and will re liquify the sealer (if it is a topical sealer) once you have use the xylene clean the area with denatured alchohol to remove any residule sealer, once you have done that scrub with a non caustic cleaner such as simple green. if the stain still remains your best option is to contact somone experienced in concrete and have them remove the small stained area and replace it. I did stamped concrete for years so i know what i am doing with this. if i saw this i would do the things i said and if it didn't ome clean i would use a grinder to remove the small section that is orange and then repour it using a high psi mix hand tinted (id mix and pour samples at home first to verify the correct color to concrete ratio) and then just use a small edge stamp to redo the texture.

Concrete and Cement

Should you keep concrete wet while curing?

Yes. Especially in warm dry weather which is the optimal environment to pour a slab in the first place. Never pour a slab if its going to rain and hose it down daily after its poured for at least a week. It prevents cracking which is caused by the warm, dry conditions which it requires to cure. Kind of a catch 22.

Being an old contractor, his comments are spot on, however let me add a few things. One of my first jobs in the construction business was to stand guard over newly poured concrete and keep it wet. I learned early on, that "slabs," such as driveways or walks took approx. 30 days to cure, and the longer one slowed the curing process, the stronger and less likely the cracks.

Invariably I started off with a hose, but if you try this on a warm or hot day, you'll find that the water will evaporate faster than you can hose it down. We took to installing sprinklers, like oscillating kind, which you could set in the middle of a driveway.

Much later, we laid 2x4's along the edge, over plastic and weighed them down with bricks, so we could flood the concrete. It wasn't ideal but flooding worked a heck of a lot better than sprinkling.

Home Improvement
Concrete and Cement
Manufactured and Mobile Homes

How many bags of concrete will you need for 30 ft 30ft 3in thick?

10 80# bags will fill about 6 cubic feet, so 375 bags should fill 225 cubic feet (30 x 30 x 0.25).

ANS 2 -

At least in my area, it would be much cheaper ordering this to be delivered by a concrete truck.

An 80 lb. bag of concrete is 2/3 of a cubic ft. of concrete. 3 bags is 2 cu. ft. So for 225 cu.ft. youll need 338 bags of concrete.

Concrete and Cement

How do you properly and safely use muriatic acid to take a sealer off a concrete garage floor so you can apply Rustoleum paint on the floor?

First, depending on exactly what sealer was used, it may not even take it off successfully. Perhaps a test is in order for you. Using muratic acid is not rocket science. Every mason uses it nearly daily, and it's more pure form is used in your pool. The key things to remember are safety glasses, proper ventilation, and "add acid to water". Read your acid documentation. Your application probably calls for 10% acid, which for me meant adding my gallon of acid to two gallons of water. I used a 2 gallon water can with a flower water sprinkler head on it. Pour it on small areas, say 3' by 3', and scrub the acid area with a plastic brush on a LONG handle. Do not bend over near the acid with a hand held brush, as there is no way to avoid breathing the vapors. For my floor, after a couple of minutes you could visually see that the acid was spent, as when you brushed it, no futher bubbling occurred. Flush well with water. The floor should feel like medium grit sandpaper if properly done. Some areas of my garage had some type of sealant. It was easy to tell when I had not gotten through it, as despite the acid wash, the concrete was still smooth. I reapplied the acid a couple of times and it worked eventually. I would recomend a mask with an organic vapor filter, but didn't use one personally. Either way get a couple of good fans for ventillation. More input from others: * I don't like the stuff, since I ahd a very unpleasant experience when using it. I know you have to be extremely careful how you dilute it, and what sort of container you use, etc. It has a lot of contaminates in it so you need to have adequate ventilation. Probably your best bet would be to call the manufacturers, if they have an info 800# most do. Or you can check out which has some really great info. on lots of "house stuff." * Muriatic Acid is also used to remove rust from steel ... and does a great job. But after the rust is gone it will continue to dissolve the basis steel, so be alert and when the rust is gone ... remove the article. Also, fumes from the acid, though you may not see at once.. will cause eventual surface rust to any steel parts in the close vacinity.

Concrete and Cement

What is workability of cement?

  • Workability is defined as the amount of useful internal work to produce full compaction.
  • Factors affecting workability
    1. Water content
    2. Mix proportion
    3. Use of admixtures
Swimming Pools
Pool Building and Repair
Concrete and Cement

What is the proper mix ratio for vermiculite portland cement mixture that will be used to repair the shell of a swimming pool?

usually 7 to 1. However, it's easier and more consistent to by a premix compound such as A-Tops brand v-lite premix. Key point to mixing premix: use a mortar mixer and don't let it mix for more than 30 to 45 seconds. Otherwise, the mix may overheat making it harder to trowel.

AnswerWe have used one bag vermiculite (4cf) to one sack portland cement. That way when you change out liners years down the road the base does not need to be redone.. AnswerAnd how much water should be used (for say 40kg portland + 4cu ft vermiculite)?
Concrete and Cement

How many yards of concrete will cover 20x20?

Depends on how thick it is. At 4 inches thick, you would nee about 5.5 cubic yards adjusting for safety. At 6 inches, you'd need about 8 cubic yards.

You can play with different thicknesses with the linked concrete pad calculator.

China and Chinese Territories
Concrete and Cement

How do you remove rust stains from a marble tabletop?

First thing to try is industrial acetone that you buy at any hardware store. Put it on a soft rag to scrub a bit. It may take several tries, but should work. Just be careful not to get the acetone on any of the stained wood.

Secondly, Bar Keepers Friend in a soft paste. On polished marble don't scrub really hard, just kind of buff the area. Rinse with water or acetone on a rag.

After you have a clean surface, reseal the stone with a professional stone sealer.

My mother gave me a couple of old marble table tops that her brother had made. Each of them had rust stains on them that had been there for years. I called my uncle and asked him if there was any way to get the stains out, he said the best way was to use alot of elbow grease and a soft rag and Turtle Wax Polishing Compound and then buff it up a little. Believe it or not it worked like a charm and they look like new.

Another idea to try(If the marble is colored,try covering with a mixture of salt and lemon juice and leave until it's worked.Rinse with water and soda mix.Rinse again.)

NEVER, EVER, NEVER use lemon juice on marble. Lemon juice is an acid and it will just etch the stone. On a polished surface it will take the polish right off.

Be careful trying either the CLR (label says it shouldn't be used on stone) or the home remedy above because it may cause etching on your marble. I've heard Singerman's Concrete Rust Remover worked, but only applying it for a couple minutes at a time.

It is advisable not to use acid cleaners on countertops. The top surface can be gradually dissolved by acids and expose the layer underneath and cause a lot of damage.

Natural Formula to Use:

A mixture of baking soda and warm water

Method to Use:

1.Make up the mixture of water and baking soda

2.Scrub stains with a soft brush or sponge

3.Rinse thoroughly with water to remove all residue


When scrubbing the stains be careful to rub gently as once the surface has been scratched it easily picks up any grease, dirt or soap residue.

Concrete and Cement

How much water to 80LB bag of concrete?

4 quarts approx.

Concrete and Cement

What can be done when muriatic acid changes your driveway concrete a blotchy tan instead of the ivory white it once was?

I would start out by using a hot water pressure washer with a store bought driveway cleaner. You can rent one at your local hardware store. Chances are the muratic acid you used mixed with oil, dirt, or soap that was left behind on your driveway. Next, while the driveway is still wet, mix a small amount of the acid with water in a 5 gallon bucket. Use a disposable dust broom or masonry broom to scrub the acid into the concrete. You will notice that the acid will foam and have a froth on top. This is because the acid is burning the concrete. You will want to rinse the area you scrubbed the acid into right away with the pressure washer. If you fail to rinse ALL of the acid...your concrete will stain, which in your case is a tan color. I've cleaned a few brick and precast buildings in my time. P.S. Don't forget to wear eye protection.

Concrete and Cement

What is the average cost of concrete per yard in Pittsburgh PA?

you need to ask per cubic yard.. and im trying to figure it out as well

Concrete and Cement

What is the use of lean concrete?

Main function of the lean concrete is to provide the uniform surface to the foundation concrete and to prevent the direct contact of foundation concrete from the soil.

Lean concrete is used under the foundations.


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