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Superior Precast Wall and basement floor question

Posted by patriceny (My Page) on
Fri, Jun 29, 12 at 12:54

Hi everyone - I am not a construction expert, so bear with me. I will try to explain this so people smarter than me with construction issues can understand it, and then hopefully give me some advice.

I am having a new house built. It is one of the most stressful things I've ever done - but that is another topic.

The builder is using Superior Precast Walls. They installed screed boards so that they could pour the basement floor, and we noticed that the boards were not pressure treated. Asked builder about it, he agreed they should be pressure treated and he would "take care of it."

Next time we check the floor had been poured. Someone removed the screed boards before the pour and never replaced them. As a result our basement floor is not as thick as it would have been if they had used the boards - because they (had to?) stop the pour lower than the bottom of the wall system. (The top of the screed board was a few inches above the bottom of the precast wall.)

The other unhappy surprise is that the bottom of newly poured floor is now several inches below the bottom of the entry door into the basement - so the mason devised some sort of mound of concrete as the landing pad for the door. I'm having a hard time explaining what this mound looks like, but basically it is not level in any direction - it looks like a pile of snow that has melted a bit. It is basically an uneven ramp down to the level of the basement floor. As you step into it from the stairway, your foot rocks either left or right because there isn't a level point on it. (You can't tile this mound - there isn't a spot on it that isn't rounded.)

So my apologies for the non-technical explanations.

My questions - how can I determine if they messed up the basement pour by not using those screed boards? (Is there a minimum depth of concrete in a basement floor?) It notes they used 3500 PSI concrete, but says nothing about depth. Can depth be a structural issue, or a performance issue (cracking?) or anything like that?

Secondly, despite my horrible description - has anyone ever heard of creating a mounded "landing pad" as a transition between the floor and the bottom of a door? Personally, I HATE it. It feels beyond bizarre to step foot inside expecting to hit a level floor, and have your foot pitch to the left or right. (Not to mention it will be impossible to finish - I had hoped to put tile there at some point.)

We are meeting with the GC on Monday to review all of this. I will be grateful for any insight anyone here may have.

Thank you!


Follow-Up Postings:

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RE: Superior Precast Wall and basement floor question

A screed board is a tool for smoothing and leveling a poured concrete floor while it's in its plastic state.

Modern residential basement concrete floors are typically 3"-4" thick, usually on top of a drainage gravel layer of another 3"-6" thick.

3500 psi (approximately 25mpa) is an appropriate strength for the floor. However, the floor is typically not structural.

The thickness of the flooring should be spelled out in your contract or approved building plans.

I've had the step-down problem in a house I built. The blocklayers should have set the door bottom lower. But it was easy enough to add a wooden landing on the inside.
Dropping an uneven blob of concrete on the floor to make up the height is pretty sloppy. They could have built a simple form--10 minutes work--attached to the wall so you would have a stable base for tile, carpet, whatever. I can't see an inspector passing the blob as a landing.


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RE: Superior Precast Wall and basement floor question

Thank you so much for the detailed response Worthy!

Unfortunately I wasn't smart enough to detail the thickness of the basement floor. We would have had ~3.5 inches with the 2x4's there, and now we have something less than that. (I'll measure it tonight, I'm guessing it must be 2 or 2.5 inches thick.) But if the thickness isn't really a structural issue then I am less concerned about that than I was.

Also, a wooden landing seems to be a far more reasonable solution that the blob of concrete approach. I know I didn't explain that well, but stepping onto it just feels so wrong - your foot expects to hit level ground inside a door!

Anyway, thanks again for your very helpful reply! :) I really appreciate it.


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RE: Superior Precast Wall and basement floor question

I have Superior Walls. I realized that true success with an engineered system depended on adhering precisely to every requirement. Your job is royally screwed up. If yours has been backfilled already, removing the concrete floor will permit the walls to move in from backfill pressure. As it is, your floors are now about 2" to not more than 2 1/2" thick if they are about level with the bottom flange on the wall sections.
I got the builder booklet from the Superior Walls installer before we even dug the basement and literally memorized it. Even took the installer to task on couple of points where he was going to cut corners. To save money, I had a friend do the excavation with his Cat 953 and I did the base gravel with my Bobcat. I did the treated screeds myself and the rebar to the base ties to prevent base outward movement on the daylight portion. The entire floor gravel base was compacted with a powered plate compactor. Not one crack in the floor.
I also did the top plates myself and used a bolt in every hole. Most builders use a bolt in about half the holes. I used the tie down straps closer than specs. Be sure the carpenters understand the proper fastening of the tie downs. One carpenter was making them look really great and they were actually holding nothing. No one would have noticed it had I not done so. We had to redo those.
The screed boards make it easy to get proper floor thickness without having to try to finish the concrete surface between every set of studs. Setting the screed boards with a laser level helps ensure that the entire floor is level and flat. My walls are the older R-5 design and the floor concrete stops at the stud faces, where the screed boards were fastened. Done right, Superior Walls are wonderful.
The installer of your walls may really want to stay in good graces with the builder and may not really take the proper stance in your favor. See if you can get the builder book. You and your lawyer can use it even if the installer does not help you. Take the case to court if necessary.


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RE: Superior Precast Wall and basement floor question

Hi Busdriver - thanks for your reply.

Please bear with me, because I'm not an expert....but can you elaborate on why you think this is such a disaster?

Everything I can find says the concrete floor in the basement isn't a structural issue. Again, I'm not an expert though. It is pretty clear the depth of the concrete isn't as deep as it would have been if they used the screed boards.

I went to Superior's website and found their instructions on how to pour the floor. It says to either use the screed boards set to the level you want, or to pour into the voids in the wall. There isn't any concrete in the voids in the wall though, as they stopped the pour just below that point.

The house is not backfilled yet. The foundation walls were installed by Superior, so I'm fairly sure they are done to specs.

I despise the impromptu ramp they devised as the transition from the door to the floor. That I plan to insist they jackhammer out and come up with a different solution. What I don't know is what problem they may have created with the thinner concrete floor - but again, eveything I can find on the web tells me basement floors aren't a structural issue.

So what problem do you think this thinner concrete floor may create?

I'm meeting with the builder Monday morning. He has been reasonably honest thus far. I can't wait to see what he says about all of this.


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RE: Superior Precast Wall and basement floor question

I stated earlier: "If yours has been backfilled already, removing the concrete floor will permit the walls to move in from backfill pressure." What do you think keeps the walls from pushing in at the bottom? Backfill pressure is enormous.
I have never used self-leveling compound. It is presumed to be very expensive. If it is suitable as a wearing surface and the bond is assumed to be suitable, perhaps your floor could be built up to the proper level with it. I doubt (and certainly hope that they did not) that they went to the effort to remove any of the level gravel base before doing the floor. And can you confirm that a proper plastic membrane was placed on top of the gravel and under the concrete? I used 4 layers of 7 1/2 mil plastic because I had it on hand, acquired at no cost. As much as humanly possible, my job was done to specifications (or beyond) and the results are complete satisfaction.
My nature tells me that if they cut corners in one place, it is time to closely inspect all the other places and things.
Do you want to live with the present floor for the remainder of your stay in this house? Ask the builder if he would want that for his house?


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RE: Superior Precast Wall and basement floor question

The treated boards I used for the perimeter screeds were 3 1/2" wide. So the top edge was nailed to the wall at 4" height, leaving the possibility that a little of the concrete might go under the board. Nothing at all wrong with that. Using boards ripped to 3" width would not be bad if the top edge is properly positioned. Placing the board top edge 4" above the gravel base insures the slab thickness.


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RE: Superior Precast Wall and basement floor question

I see the Builder's Checklist from Superior requires a 3.5" thick floor.

You can raise the floor with an additional pour provided proper techniques are used and you add at least two inches of concrete.


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RE: Superior Precast Wall and basement floor question

Thanks so much guys - I really do appreciate all the information.

I am fairly certain they used the vapor barrier. At least, there was vapor barrier there for them to use laying on top of the stone before the pour. I suppose they could have picked it up and taken it away with them....but I'm going to make myself crazy if I start going down that path. :)

I also spoke with a concrete supplier, who told me there are really good bonding agents they can use to do another pour on top of this floor as long as the new pour is at least 2 inches thick. (Sounds exactly like what Worthy said. :) ) Jackhammering out the concrete hump/ramp and doing another 2 inch pour takes me right up to level with the bottom of the door.

Again, I really do appreciate all the information. We are meeting tomorrow morning, and trust me, I plan to use the "would you want this in your house" line.


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RE: Superior Precast Wall and basement floor question

Since Superior Walls details are not in the building code, the code accepts engineered systems, or alternative details to the code, where a Registered Engineer has signed the plans for such details. I know of at least one nearby jurisdiction that carefully matches the engineered drawings/specifications to the work actually done. Other jurisdictions are more casual about it.
The point is that deviations from the engineered specifications are building code violations.


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RE: Superior Precast Wall and basement floor question

Thanks Bus Driver.

We actually had our local code guy look at it. He said there wasn't much he could do. He agreed the concrete transition they devised from the door to the floor was unlike anything he had ever seen before, but he didn't feel he could help us beyond that. (He's been a decent guy so far in this.)

We came to an agreeable solution. They are removing the "river delta"/lump of concrete. They claim they did that on purpose but that since I hate it, they will remove it and take the floor back to level/smooth it out. I'll have about a 2 inch step down to the floor, but that is ok with me.

As far as the floor, the GC swears there is 3.5 inches of concrete there with the vapor barrier and the right amount of stone. I got the "isn't a structural component" line too, which I expected. He seemed genuinely surprised that I was so concerned about it, and I didn't get the sense that he was hiding anything or trying to pull a fast one.

He has seemed honest so far. So, at this point I'm going to trust him. Fingers' are crossed though and we'll see how the rest of it goes.

Again, I do appreciate all the kind help from both you and Worthy. :)


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RE: Superior Precast Wall and basement floor question

My walls are from 2003, but I doubt that much has changed on the specs since then except the R- value is now upped to 12. My door opening from the factory had a concrete bottom flange across the opening. It rests on the compacted gravel base as do the bottom flanges of the wall sections. Outside on the door bottom flange scratch down to expose the bottom edge at one narrow point and measure that vertical thickness. Should be about 4". Now if your floor is 2" below the top of that door opening flange, how can both the stone and concrete inside be as your GC states?
The wall section flanges are about 2 1/2" thick.

Your project is a mess. To have 4 inches of concrete in the floor, the stone under the floor would have had to be removed to 2" below the level of the bottom edge of the bottom flange of the wall sections. The math works no other way. Another test is to take a rotary hammer bit, probably 1/2" diameter, and mark it at inch increments, then drill until it breaks through noting which mark was nearest the surface when the drill broke through. The hole will permit measuring with a narrow tape measure, hooking on the bottom of the floor slab, if desired.
This probably should be my last post. You really need some on-site expert help. The GC is not on your side.


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RE: Superior Precast Wall and basement floor question

Hi Busdriver - I don't know if this will make you feel any better, but I know it made me happy. :)

I have a newer version of Superior Walls, called the Xi Plus Wall. Superior's literature clearly says the footer beam is 4' thick, and that the 'standard floor slab may be poured equal to the height of the footer beam, eliminating the need for an additional screed board, saving time and money in the construction process.'

So while the verdict is still out on the GC, I am fairly confident the floor has been poured according to Superior specs at this point.

Here is a link that might be useful: Xi Plus Info


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RE: Superior Precast Wall and basement floor question

I sincerely hope that your belief reflects reality. But why then did they (Superior Walls) create a door base beam that is too high if the other specifications are in compliance? Suppose that they are referring only to the door footer beam as 4". What other footer beam could they be referencing? If the footer between the studs is also 4", then why screed boards under any circumstance? If you measure up from the BOTTOM edge of the OUTSIDE of the door footer, then you will know the level of the gravel base under the walls. The bottom/lower edge of the door footer is even with the bottom of the footers on the wall sections.
Once you know the thickness of the door opening footer, use some leveling device to establish a level line from which you can measure down to determine the footer thickness between the studs in the walls sections. Probably less than 4".
I am far from convinced that all is right with this installation.


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RE: Superior Precast Wall and basement floor question

I looked at the SW website. The XI+ has a shiny foil face exposed between the studs. The XI (R-12) has blue styrofoam face exposed between the studs, as does the R-5 which I have. So it is easy to visually identify the system being used.
I posted above and hereby amend it.: "Once you know the thickness of the door opening footer, use some leveling device to establish a level line from the top surface of the door opening footer on the inside from which you can measure down to determine the footer thickness between the studs in the walls sections."
Before you accept the present situation, call Superior Walls about the door footer beam standing proud of the floor. It is not supposed to be that way!

Superior Walls

937 East Earl Road
New Holland, PA 17557
Phone: 800-452-9255
Fax: 717-351-9263


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RE: Superior Precast Wall and basement floor question

Well, I think I'm ok, fortunately.

(The walls are the Xi plus - they shimmer in the sunlight. Heck it felt like you are in a pizza oven down there in the sunlight. :) I felt so bad for those guys working down there over these past hot days.)

The hump is out, they cut it back down to the vapor barrier. So I can see that there is about 4 inches of concrete in the floor (and I saw the vapor barrier underneath it).

I was told the door sits up like that to allow for the extra height in case it is finished with screed boards - but that using screed boards is not necessary with this new wall. Had they actually USED pressure-treated screed boards the floor would be almost level with the door...but since some doofus used untreated wood the GC had them pulled out and didn't replace them.

Do I wish the floor was more or less level with the door? Yes, I really do. But at this point I think it is the lesser of 2 evils. The floor that is there looks good, and it is finished in a manner that is "just fine" according to Superior. I suppose I could pitch a fit and make them do the whole bonding agent/another 2 inch pour thing...but I'm afraid all that is going ot do is tick off the GC, and it adds just one more thing that could go wrong. Besides, I'm having the floor finished off with tile down there eventually, so that will make up some of the height too. If we add another 2 inches it could actually make it too tight to do tile underneath the door.

I appreciate all the help. Hopefully this closes the chapter on the basement. Now we'll just have to see what can go wrong on the floors above it. ;)


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RE: Superior Precast Wall and basement floor question

Based on what you posted, here are my thoughts. If screed boards had been placed on your job with their top edge level with the top edge of the door opening footer beam, then your floor would be 6" thick. Is Superior Walls seriously suggesting that is their design intent? A beam 2" higher that the floor is ripe for a lawsuit when someone stumbles over it.
My floor with the R-5 walls is level with the top of the door opening footer beam. I think that was the intent of Superior Walls and that is the only option satisfactory to me.
"so the mason devised some sort of mound of concrete as the landing pad for the door." I was thinking that the brick mason added this on top of the floor created by the concrete contractor. So now it seems that the hump was integral to the floor and was done by the concrete contractor as part of the floor project. So now the floor will be patched.


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