incomplete drain

jburns

I am building a new shop and have a 16' trough drain in the floor. The problem is that the bottom of the drain is not cemented. I think the contractor forgot to do it. Would the proper order to build this drain be to do the bottom first with rerod to tie into the walls of the drain in the next step? Is there somewhere I can find commonly accepted construction practices for this type of project?

Bonus

Can you give a little more info? How wide is the drain, How deep? Where does it go to? What purpose will it be put to? If it is what I have imagined I don't see why you can't simply pour concrete into the bottom and smooth it out at an appropriate slope, but I may not be understanding what's going on.

jburns

The drain is 12" wide and 10" deep. It is a washbay for a shop and has a four inch tube raised 3" which goes to a ditch. There is no rerod to tie the bottom to the sidewalls which will let the bottom eventually separate from the wall.
This will let water get under the drain which I am told could cause cavitation under and around the drain.
Thankyou

powrus

Based upon your posts, I visualize a sixteen foot long trench in the [concrete] floor of your shop, the trench being twelve inches wide and ten inches deep. Is this correct?

Somewhere near the exit point of the sixteen foot trench exists a 3 inch tube. This tube collects the wastewater from the sixteen foot trench and then directs that wastewater to a ditch which is located outside of the shop. Is this correct?

You are concerned that the 3 inch tube may not be stable in its present state and would allow wastewater to leak around the tube, thereby eroding the soil around the tube. You would like to secure the 3 inch tube it to the outside wall of your building. Is this correct?

Answers to these questions help us to understand your dilemma. Thanks.

jburns

We are actually using a four inch tube which is not the problem. We have no cement in the bottom of the drain period. You accurately described the type of drain we have. When I brought this to the contractors attention he said he planned on doing it later. All of the other concrete work is complete as far as he is concerned. He left ne rebar or anything to tie the floor of the drain and the walls together. I talked to an engineer today and he said the proper method of construction would be to do the base first with keyway joints and rebar to tie the sides to the base. He said it is also very important to use a water seal tied into the base and walls. If water seaps through the joint it could eventually cavitate under and around the drain and shop floor. I also have a problem with area where my 20' overhead door will seal to the floor. There are several hills and valleys in that span of up to 1/2". My door company says they cannot guaranty the door will seal. The high spots are already at the floor level so grinding is not an option. You can see the foor is uneven very easily and can feel it walking across it. My contractor says the work is good.
Thak You

Bud Cline

Your contractor is goofy that's what he is.

The drain IS NOT constructed properly but is not lost. I would compact the soil in the bottom of the drain trough and pour some concrete in there and finish it off smooth. The fact that it isn't tied to the walls is only a minor concern because there is more than enough natural irregularity in the walls that the base casting will lock itself to the walls anyway and won't likely go anywhere.

You could then either hot-mop or cold-tar the base and walls which will seal the junctures and eliminate any cavitating under the trough.

I would allow the bottom of the drain tube to be about two inches above the finished bottom of the trough. This would collect any solids that may get into the trough over time and could be cleaned from time to time. That's better than allowing any water-flow to carry solids into the drain pipe that might settle mid-pipe and cause an obstruction over time. This way the drain tube can't be filled with mud that is being washed from the trough during use.

OK, now that door.
This too is obviously a fiasco but the floor can be ground down slightly. I would strike a straight line equal to the inside of the door and begin grinding the high spots from that line outward and along a path under the door seal. A sharp edge at the point of just inside where the door sits won't hurt anything and the outside can then be ground off to allow water to run away from the door.

Don't let the door company tell you the door can't be adjusted downward a little, that's nonsense, they can all be adjusted from time to time. Of course it won't seal like it is but somebody with a little imagination can make all this work and work properly.

I wouldn't be recommending that concrete guy to any of my friends in the future either.

The only other option would be to have the concrete contractor start cutting and removing concrete in both areas and start over and I think he would try to buy-you-off before he went to that trouble for free.

Tscarborough

I would do the same, but I would dig the trench enough to key on the bottom of the sides and paint on a bonding agent at that joint to seal it.

jburns

Thank you for your suggestions I am taking them into consideration. I have a company coming to look at it tomorrow that does cutting and grinding. A friend who is an engineer said I should also have the corners of the drain cut to avoid the inside corners from cracking. He also said I could do a stainless steel liner in the drain. I had planned for the tube to be about two inches from the bottom of the base so your idea will work. I am thinking on the door of grinding the floor from a couple of inches inside where the door sits to the outer edge at a gradual slope. If they think they can get it sraight. My door guy can lower the door okay. The problem was that the area across the door is really uneven. If we grind it I will try to find some kind of coating for the floor to give it a consistent look. Epoxy? We will have fork lift and skid loader traffic. The contractor was recommended by the people who sold me the steel building. He was also to erect the building. I thought I would have less trouble dealing with one contractor. WRONG! I did not try to do this on the cheap. This is a 60x80building with a ten " foundation, 6" 4000 pound floor,and more steel than a boat headed for china. I have not paid for the concrete yet and have hired someone else to erect the building. The contractor was the first person I have ever fired. Felt Good. Please add anymore ideas you can.
Thank You Sorry This Was So Long

Bud Cline

You should hold "retainage" on the contractor in an amount sufficient enough to cover the costs of the corrections of the trough and grinding of the concrete at the door.

Did you pull 'samples' of the concrete at casting time to insure you were getting the mix you contracted for?

jburns

I am getting esimates on the corrections needed to bring the concrete structure up to an acceptable level. We are taking plaster cast to record the depth of the valleys in the door area. From our measurements it looks like they range up to 5/8 of an inch. These will be accurate records should we need them later. A concrete sawing and cutting company looked at it today and think they can cut it but want the door installed first to gauge off. I am going to have a stainless steel trough consructed that will line the drain area. I did not take samples of the concrete but the mix seemed to be fine. It's just the finish work that's bad. It has since rained here and now I have puddles in several large areas of the building that are up to 3/8 of an inch deep. Is this normally acceptable. I know concrete is difficult material to work with and don't want to be to picky. I paid extra to have this done with riding trowels and lasers. I have not paid for anything yet. They tried to collect saying they were done and expected payment but I discovered the drain was unfinished. They had filled it half full of chunks of cement and trash. Lucky I checked it. Also if anybody knows of a color finish I can use on the floor that will stand up to fork lifts and skid loaders please let me know and I will check it out. I really appreciate all of the help. I didn't think I would have to learn this much about concrete. I was to trusting. It pays to talk to professionals you trust before starting any project.

Thank You

Bud Cline

JB,

There are "acceptable level & plane tolerences" for the industry but I have no idea what they are for a slab that size. You could locate that information on the Internet by going to one of the concrete organizations and start there.

But for example:
In ceramic tile installation the condition of that slab's surface would have to be within 1/4" in 10' in all directions for it to be considered "in-plane" and acceptable.

As far as a commercial finish product I can recommend the Tennant Company. Years ago I used to install their industrial coatings on concrete warehouse floors in Dallas. All kinds of rubber-tired equipment ran on those floors.