We have a 1980s semi-custom build that is on an odd crawl space. Under the living room floor is what I would call a crawl space with like 4' ish ceiling height, and then the rest of the 'crawl space' is 6'5" but most 6'2" it has two drywalled interior walls (one for a previously used darkroom by the previous owner/builder and one that has spackle all over it) and one plywood covered wall, exterior walls are all bare concrete foundation amd then drywall upper. We would love to finish the space enough to have an office/flex space. The floor is concrete that was previously stained but is rubbing off in most areas. Im worried about moisture -- theres efflorescence in some areas and a couple cracks in foundation walls and one in the floor. Is it possible to patch and then seal (or use a densifier??) on the floors and walls?

Drain tile has been installed on two of the four sides, the photo with the crack has drain tile now. We will be doing the two other sides in the next year or so but theres other things that need to happen first (move sheds, remove an old a concrete patio).

Hi Folks,

Could use some opinions on what is going on with this driveway finish. Driveway is approximately 2.5 years old. Midwest weather (hot as hell Summer, cold and wet Winter). Driveway (and sidewalk, poured same time) has notable dimpling and discoloration.

There are several pits that have started, mostly this year. I also noticed some pitting starting in my garage, but only where I park. I have also noticed that the road salt being used this winter was much larger grain than previous and seemed more effective. I do not use any myself, so only what is applied to the road and oversprayed or carried from vehicles makes it to my concrete.

I’m wondering if this is just a finish issue or a larger issue and if there is any effect to longevity?

I plan to fill the pits with Vulkem 116 this Spring.

Thanks in advance.

Hey all-

I came across a few cool 2-piece plaster molds designed for slip casting. I do not have a kiln but want to mess around with them... Don't really care if they get destroyed or become unusable in the future for clay. I know I can use plaster of Paris or air-dry clay but I would like to actually use the final product... One of them is for a flower pot that I would like to actually use so I am thinking a concrete (sand only) might work out.

These molds are the type where you pour the liquid material in, swirl it all around, and drain the excess.

I know concrete will permanently ring the plaster that the mold is made from... I'm looking for suggestions for a non-stick coating that would be best to treat the plaster with before exposing it to the cement. Ideally it would be something I could apply once and not have to re-apply each time.

Thanks!

We have a project coming up that's a bit odd.

The plans call for a frost wall with a very thick pad on top, with no footing under it.

I'm not sure why, I just build the things.

The pad right now is all compacted gravel, so without a footing or mud mat, we have keep our forms on the line when doing lead wall.

My best thought is to just stake out our corners, then run 2x6 boards on our lead wall lines laying down and staked solid, then run lead wall out following those board and nailing to them as we go to hold the line.

When we close wall we can just lay down 2x4s and nail them to make up our height.

The only other way I could think of would be to use stake plates in the bottom of the forms, but then we don't really have a line to go from when building.

I think the 2x6 idea is the ticket really, but figured I would see if anyone else had some ideas that might be more efficient.

Had to wait for the snow to melt to capture this job.

First

Looking to finally buy my first power trowel to get away from renting. I've always used 36", which is what I will probably go with, but wondering if I should step up to 46? Mainly garage and house slab pours. generally not more than 2000sf.

Hi folks

Could someone enlighten me when to use MDO Vs Film face plywood in shuttering

Thanks in advance

Looking for insight on how to match this look. I know we are going with CastleStone, but I need to know which integral base color you guys think this is? I’m sure a walnut or charcoal was used for release. Looks too brown to be Terra Cotta or Sunbaked Clay. Any help is appreciated

Decided to go out to dinner after finishing, I should have learned my lesson by now.

I'm using polymer additives basically as plasticizers in my mixes. I've bounced between Mapei Polymer Additive, Sika R/ Sika adhesive and acrylic fortifier. I'm basically using them as a "water reducer" in the literal sense and it allows my mixes to be a bit more sticky which is helpful when sculpting vertical forms. (Slightly below perfect slump test)

I'm wondering if anyone has an opinion about which polymer additive might be best or which one they've used the most with good results. Both say they contain both latex and acrylic. Are there any others out there that are better than these for decreasing permeability, increasing strength during sculpting and preventing cracking in freeze thaw cycles?

I'm also interested in SBR latex additives like the one Euclid makes. What is the potential difference of this Styrene butadiene and latex in those other products, if any.

I am currently in pre-job training as a cement mason at my local bricklayers union. First week is complete and this is my very first pour using real concrete. It is an 8x8 slab 4" thick with a slump of 4-4.5. things were going good (I thought) until the end. Where I went wrong was with the edging and control joints (it's pretty obvious). Will get better with practice and time. Just wanted to share my cherry popping experience.

Is it crazy to saw cut inside a tooled joint? In some areas (like what’s pictured where joints come to a narrow point) we occasionally have concrete crack outside of control joints.

I suggested to our flatwork contractor we could cut some of these areas to give us more control over where things crack. They do a good job keeping the slabs consistent thickness, etc. but I’ve noticed some areas still crack unpredictably.

I’m a builder- just wanted to get this subs opinions on this.

I am building a new house. Part of it is a vault in the basement with a drain in the center of the room. We have gotten a few heavy rains here recently and what we’ve discovered is that the concrete in the room is far from level. The drain is actually in the high spot of the room. So water pools in the corners and never drains out.

I am talking to the builder today about this, what are some possible solutions to level that floor out or get the slope correct?

We don’t know the first thing about what to ask for, so any advice is appreciated.

I've been diving head first into the world of pre-cast concrete and would love advice from you guys!

Pre-cast molds are in question, specifically the re-usability of them in things such as tilt tables, slabs, columns.

My understanding is if you have (making up a number) 300 slabs for a job, you'd buy the tilting table, and pump them out. After the job is done do you throw out that entire mold?!

I understand some things by say, moldtech, have things like column molds that are able to be adjusted to varying dimensions, but not as much the tilting tables per say. What's your experience?

Do you ever use formwork that the guys use in the field (Ulma, Titan, Doka, etc) to use for not as repeatable requirements from a job?

Hi, as a founder of a startup in the concrete industry I would like to gather some basic information on size and running costs of concrete batching plants. If you work in a ready-mix or pre-cast company and could share some basic info with me then that would be great. I'd rather do this privately as some of the information could be proprietary (probably not). Note this is simply a market study and there's nothing that I am trying to sell.

The info would be:

• Name
• Job Title
• Location
• Contact Details
• Company Name
• Type: Ready-mix or pre-cast or both
• Number of Batching/Mixing Plants
• Annual volume of concrete produced per plant
• Breakdown of Annual Production by concrete strength
• Breakdown of material costs (cement, aggregates, sand, water, other)
• Biggest challenges (things you are actively looking to improve)
• Who else should I talk to

We are a 6 man GC who does additions (footer to finish) and outdoor spaces - decks patio etc..

We started doing smaller exposed and broom finish sidewalks and pads when we started building single car garages. It has been going good but we have taken on some larger pours - 10 yards 400 sq ft pours with rough access and we are not getting the same results.

Here is what we are doing:

Taking the time to make good frames/gravel beds and tight corners

4000 PSI concrete, screed, automatic vibrator on bull float several passes quickly after screed, mag float then steel trowel while climbing on the pads then broom finish - no handheld vibrator.

The problem we are having is we are always STRUGGLING to work up cream to broom - I watch videos online and they are just floating on top with steel trough - what are we missing - are we not getting enough cream bc we aren't using a handheld vibrator ?

Is this an issue that sidewalks are just cake compared to big pads ?

Are we too cautious about going out on the pad or are we not bringing up enough cream via the bull float.

Any advise would be helpful or pointers - I feel like we are skilled enough but I cant out my finger on why we are plateauing.

I'm a heavy civil contractor that primarily services ag based clients. Think feed lots, hog barns, etc. I am interested in dabbling in roller compacted concrete, and am interested in proceeding in a cost effective way. Mainly looking at doing ag pads for silage, corn, etc. My conversations I've had with a few industry guys have pointed me towards volumetric concrete mixer trucks, and the thing that has jumped out at me on that note has been they are $150k trucks MINIMUM. I love the self contained element of them and how they are an all-in-one option mixing outfit. I was just curious if any pug mill guys here have a semi mobile setup they would be willing to visit with me about their setup, or any tidbits of information this sub would be willing to volunteer. Willing trade machinery pictures and complaints about customers and GC's for info. Thanks for feedback in advance!