Skip to main content
18 votes
Accepted

What is this white powder on my foundation?

Looks like effloresence to me, which itself is not harmful, but possibly a symptom, mainly of water movement; I would check perimeter walls for further signs of water infiltration, and make sure water ...
SqlACID's user avatar
  • 1,262
16 votes
Accepted

Contractor is installing a vinyl fence and posts but is not using any water with concrete. Is he doing it right?

I put some posts into concrete - made a dry mix and tamped it down. Next day it was just about done - the mix absorbed moisture from the surrounding soil and was fine. If you need a really smooth ...
Solar Mike's user avatar
  • 27.7k
12 votes

Contractor is installing a vinyl fence and posts but is not using any water with concrete. Is he doing it right?

Unless you are in a extremely dry area this is fine. The concrete mix will absorb moisture from air and surrounding soil and will slowly set. Usually a couple of days is all it takes. Some rain or a ...
Tonny's user avatar
  • 745
11 votes

Contractor is installing a vinyl fence and posts but is not using any water with concrete. Is he doing it right?

This is a common technique for setting posts in the ground. Here is a video from Quickcrete that explains how to do it: Quickcrete Dry Mix Post Setting
jwh20's user avatar
  • 23.4k
8 votes

What is this white powder on my foundation?

Efflorescence, salts rising to the surface due to presence of moisture. Common in cementitious materials where water is present. You can wash it away with mild HCL solution but the stains will remain....
Jimmy Fix-it's user avatar
8 votes
Accepted

Is it OK if my Durock cement board got wet?

Durock and similar cement-based products are designed for uses where it may be exposed to water. It's not waterproof but it will not disintegrate or lose its strength when wet. You should allow it ...
jwh20's user avatar
  • 23.4k
6 votes

Quikrete didn't absorb much water. What did I do wrong?

It's fairly simple if your going to put it in dry like that. Put a bag in, then a gallon in, and so on. Don't put 4 bags in a narrow hole and expect 4 Gallons of water to penetrate all the way through ...
Anthony Porreca's user avatar
6 votes

Contractor is installing a vinyl fence and posts but is not using any water with concrete. Is he doing it right?

This is perfectly fine unless you live in a desert where it never rains. I've seen Florida Public Works workers build a concrete catch basin for a large pipe that passed under a road, and they used ...
MTA's user avatar
  • 11.4k
5 votes
Accepted

Will a cement mixer extend the working life of mortar?

A mixer might help you mix smaller batches more quickly, so that you can easily adjust the size of a batch and keep up. But most mixers will make you think you should be making an even larger batch, ...
Ecnerwal's user avatar
  • 218k
5 votes
Accepted

How can I fill this gap between concrete and cement board?

I ended up filling the gap with tile thinset and cement board tape.
byte's user avatar
  • 195
5 votes
Accepted

How to properly patch the "scar" in the wall after the door removal

I can understand your timeline and it is possible. In my 5+ decades of home repair and remodeling I have had to do the same type of repairs. Here is the way I do it: Day 1- Clean away loose debris ...
RMDman's user avatar
  • 31.2k
4 votes
Accepted

Quikrete didn't absorb much water. What did I do wrong?

Bagged concrete dumped in hole dry can work but is not ideal. With a clay base the hole is like a pipe. Adding water to the top the mixture will absorb water a few inches down then create a seal. It ...
Ed Beal's user avatar
  • 103k
4 votes
Accepted

What's the best way to level this basement floor?

My family remodeled and has dealt with old and new layers of cement. I suggest the following plan based on our educated, though non-professional experience. Leveling Old Cement Floor Preperation If ...
Micah W's user avatar
  • 164
4 votes

Disposal of hydrochloric acid

You can neutralise the acid by mixing with alkali. However, be careful. You will need quite a lot of something like baking powder. Or if you have any left over - cement powder. Add a small amount ...
Chenmunka's user avatar
  • 1,286
4 votes
Accepted

Is this retaining wall failing?

The wall may have been built that way but I doubt it, the wall may have shifted over the years and is stable now. The only way to know is to drop a plumb bob from the upper decking just in front of ...
Ed Beal's user avatar
  • 103k
4 votes
Accepted

Can you "refresh" half-dried concrete just by mixing in water?

One thing to consider is that concrete doesn't really "dry" like mud. The water is part of a chemical reaction that hardens the mixture over time. Once the concrete starts to get thick and lumpy, ...
JPhi1618's user avatar
  • 28k
4 votes

Can I create concrete driveway with forms to get the paver stone look without the need for all the aggregate beneath?

If this was just a patio I'd say you have a good chance of getting some satisfactory results except for the fact that it would be about 2.5" above grade and there's be the possibility of tripping over ...
JACK's user avatar
  • 81.8k
4 votes

Proper deck post installation

If I understand your description you're concerned because the posts are encased in concrete with no gravel under the posts. It would have been good to have gravel under the posts for drainage but it's ...
HoneyDo's user avatar
  • 8,784
4 votes

Should Cement Patio be Poured Level with Foundation?

I would pour it below the foundation level for several reasons. First if the same level it would be easy for a heavy rain to end up inside. In my current state and 2 others I have lived in the ...
Ed Beal's user avatar
  • 103k
4 votes

How to properly patch the "scar" in the wall after the door removal

I would like to backfill much of that scar with some cement product, but I think you could use a setting-type joint compound as a finish coat on top or entirely (no cement product). Setting-type joint ...
blarg's user avatar
  • 610
3 votes
Accepted

bathroom pipe joint leakage behind the ceiling tiles

PVC pipe like that is relatively easy to repair. The general concept is that you cut out the bad section including any fittings and then install new pipe and the necessary fittings to join back to the ...
Michael Karas's user avatar
  • 65k
3 votes

What is this white powder on my foundation?

Efflorescence, salts... you'll also see it on brick faces. Rookie concrete workers. Was your basement floor poured in winter? They add more "chemicals" into the mix, keep it from freezing, keep it ...
Joel Huebner's user avatar
3 votes

How to repair my concrete slab porch.

Patching rarely works out, structurally or aesthetically. If you want the cost effective remedy then go with smashing it up and installing properly supported decking material. This will likely involve ...
Jimmy Fix-it's user avatar
3 votes
Accepted

What is an alternative to a cement truck that would allow more working time?

The time from when the cement, water, sand and particulate are mixed till the time the mix should be in your forms is limited. That is a primary reason that a delivery truck can only stay at your lot ...
Michael Karas's user avatar
  • 65k
3 votes
Accepted

outside cement wall chipped

You can, and should wait until the overnight temperature is above 40. Working with any masonry products in low temperatures brings a bunch of complications you don't need. If you don't mind a slight ...
Matthew Gauthier's user avatar
3 votes
Accepted

Recommended paint for outdoor cement patio

I would suggest using a colored sealer instead of paint. It is available in several color options. Sherwin Williams is just one of the brands I searched. The sealer will penetrate the concrete so ...
mikes's user avatar
  • 11.4k
3 votes
Accepted

Removing pole and concrete base from yard

This is the remnants of a natural gas or propane grill, gas heater, or perhaps a gas lamp. The flared tubing fitting and old control valve stem are the giveaways here. Look around the structures ...
Jimmy Fix-it's user avatar
3 votes
Accepted

How to patch small holes in concrete slab basement floor?

You can use a variety of patch products. Premixed concrete patch would work. Platinum patch Vinyl spackling For holes that small i would use the vinyl spackling. You can sand it down if you ...
Alaska Man's user avatar
  • 13.6k
3 votes
Accepted

Which cement or mortar will give best result when creating low water diversion barriers?

Hydraulic cement sticks to wet fine, but you may need to abrade the surface to get to clean concrete, as it won't like a greasy, dirty or otherwise befouled surface. However, what I would actually ...
Ecnerwal's user avatar
  • 218k
3 votes
Accepted

Lard as release agent?

The lard will work fine. The laminated wood would give you smoother sides and bottom.
JACK's user avatar
  • 81.8k

Only top scored, non community-wiki answers of a minimum length are eligible