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Jerome W. Young
11-06-2008, 02:59 PM
Ithink this is a Mercedes home. I am not familiar with this type exterior walls. It looks like a bunch of precast concrete panels lined up. I found that the stucco on the outside is cracking from top to bottom at every panel seam. Is there something that maybe they did not do over the seams to prevent this from occuring? The neighboring houses did not have this problem and were of the same construction.

Darrel Hood
11-07-2008, 04:35 AM
Do you have any photos?

Jerry Peck
11-07-2008, 10:01 AM
Jerome,

Not having inspected any of those types, I would think that some type of separation membrane should have been used over the joints prior to stucco. That would allow for slight movement of the joint without that movement transferring through to the stucco.

Possibly something as simple as fiberglass mesh tape applied over the joint to reduce the forces which would cause the cracking (put which is not really a separation membrane), to a true separation membrane which literally allows the stucco to not be bonded to the walls, but to the separation membrane, where the separation membrane spans the joint.

Ted Menelly
11-07-2008, 11:04 AM
Just as in brick corners, or coins as some call them, mostly a straight line, you will almost always have cracks in long straight runs like that. Unfortunately a control joint at every single juncture at the panels would be almost the only way for the cracks not to show up. Homes are going to move with wet then dry, hot then cold , and are always going to expand and contract though out the day and year. You are going to wind up with cracks with those long top to bottom joints.

William Brady
11-09-2008, 07:24 AM
I guess the question is why is the other home not cracking and this one is. I don't have the answer, it is a good question. It would be nice to get the answer for it.

Jerome W. Young
11-09-2008, 06:02 PM
picture from inside the garage

Jerry Peck
11-09-2008, 08:15 PM
It looks like a bunch of precast concrete panels lined up.

Jerome,

That photo looks like solid reinforced poured concrete where they used form panel sections which were vertical.

The roughness at the joint lines which protrude out from the wall, were there hard and concrete, or soft and pliable like sealant? If they broke off like concrete, that would be the concrete paste getting between the forms when they vibrated (consolidated and re-consolidated) the concrete as it was poured in the wall.

Was there associated cracking on the exterior at those locations?

How long was that straight section of wall? Could be a contraction joint (solid poured concrete walls are as long as they will ever be when just poured and curing - they are hot (thermal related expansion) and wet (moisture related expansion). If the wall is very long at all, curing will cause the concrete to contract, which could leave cracks like that.

If it is a solid poured concrete wall it will have, make that *should have*, enough steel in it in both the horizontal and vertical directions that I would not be concerned about that cracking on the inside (on the outside, it would be a moisture intrusion source).

Jerry Peck
11-09-2008, 08:29 PM
Jerome,

Go here ( Construction process by Matrix Concrete Systems-New construction in Florida (http://matrixconcretesystems.com/Construction_Process.htm)# ) an click on the 'High Speed' link (or the slower link if you do not have a broadband connection - the 'High Speed' link still takes a while to download the video).

I think that is what you are looking at.

Here is another look at something similar: Concrete Wall Homes Demonstration (http://www.affordablefloridahomes.com/Concrete-Wall-Construction/concrete-wall-demonstration.html)

Darrel Hood
11-10-2008, 05:06 AM
Regarding the comparison to nearby homes, were they built by the same builder using the same methods? If so, I suggest that the builder may have expertise to help answer the question.

I have worked several projects with differing types of concrete walls, but I have yet to see a wall covering applied directly to the concrete wall. The expansion/contraction mentioned several times here is certainly one of the reasons. On my projects, there are always furr strips, styrofoam forms, styrofoam wall board or some other intermediate "movement buffer". Perhaps that is the key to your answer.

Hope this helps,

Darrel Hood
DILIGENT PROPERTY SERVICES

Jerome W. Young
11-10-2008, 06:01 AM
Jerry,

I think these were pre-cast walls? I dont think they were poured in place. Is that even an option for residential?

Jerome W. Young
11-10-2008, 06:36 AM
Was there associated cracking on the exterior at those locations?

Yes, on every one. The seam is hard and the stucco exterior is cracking from top to bottom. Fill the cracks/ paint and it should be fine? Ithink the cracking is from exactly what you say, but the questions is... is the shrinking/contraction over?

Fred Comb
11-10-2008, 08:47 AM
Ithink this is a Mercedes home. I am not familiar with this type exterior walls. It looks like a bunch of precast concrete panels lined up. I found that the stucco on the outside is cracking from top to bottom at every panel seam. Is there something that maybe they did not do over the seams to prevent this from occuring? The neighboring houses did not have this problem and were of the same construction.

How old is the house and what is on the other side of the wall shown in the photo? If soil, how high and what type?

Jerry Peck
11-10-2008, 08:54 AM
I have yet to see a wall covering applied directly to the concrete wall. The expansion/contraction mentioned several times here is certainly one of the reasons.


Darrel,

Most of what saw when I was in South Florida was "wall covering applied directly to the concrete wall", both to concrete block walls and poured concrete walls - namely .... stucco.

Properly cleaned and prepared, concrete block will take stucco directly, poured concrete will require a bonding agent applied to the concrete to allow proper adherence of the stucco.

Jerry Peck
11-10-2008, 09:26 AM
Jerry,

I think these were pre-cast walls? I dont think they were poured in place. Is that even an option for residential?

Jerome,

Yes, there are some companies which sell house plans and precast panel constructed to fit those specific plans. The slab is poured, the precast wall panels set in place, then the house finished in the normal manner with trusses, etc.

My daughter built one over in Williston (near Gainesville, Florida) where the precast wall sections were made in Jacksonville, delivered to the site, where the wall sections were set on the slab. I was not able to see the house under construction when the panels were being installed, but saw it afterward. The walls come with foam insulation attached to the inside, with the furring strips pre-attached to the walls (the wall sections are poured into the forms, then the insulation and furring strips, with anchors already in them, are placed on the exposed side while the concrete is still in its plastic stage and then left to cure. The foam covering the concrete now also serves as a proper curring cover for the concrete. When the concrete has curred, the wall panel sections are tilted upright and stacked for delivery.

I did not see the exterior walls prior to stucco as almost as soon as the walls were set and the trusses set, the scratch coat was applied to the concrete walls. All I got to see was the inside, which was all 1-1/2" thick foam (the furring strips were 2x2). To run wiring and plumbing down the walls, the foam was cut out where the wiring or plumbing ran.

Something like this: Manning Quick Wall, Precast Homes, New Home Construction, Commercial Construction (http://www.precast-homes.com/watchavideo.html) (states they can erect a 2,000 sf home in less than one day, my daughters home was 1,850 sf, it was erected in less than one day)

Here is a unique video where they were test typical wall structure types: YouTube - How Precast Concrete Walls help protect your home. (http://www.youtube.com/watch?v=Wm-dFyh2C98)

As you probably noticed, the precast panels are not narrow, like the joints in your photo are, however, the forms for the poured-in-place concrete walls are narrow, just like those in your photo.

William Levy
11-10-2008, 10:16 AM
Hi everyone,

for info on the solid wall pefab system go to Royal Concrete Concepts - Concrete Construction / Builders, New Custom Hurricane Resistant Homes and More (http://www.royalconcreteconcepts.com/s_royalwall.php)

don't forget to check for radon..these homes should be very tight and from looking at one down the street seem to be able to use a smaller AC?

Bill

Associated Radon Services
Associated Radon Services | Certified Radon Analytical Laboratory | Radon From Granite Testing | Radon Testing | Apartment Radon Testing Specialists | Building Material Radon Emanation and Soil Radium testing | Radium-226 | condo radon testing | e-pe (http://www.radonserv.com)

Darrel Hood
11-10-2008, 01:15 PM
Jerry Peck,
I don't know if we are seeing a regional difference or if I just haven't "seen it all" yet. In the cases of stucco directly on concrete, how do they allow for the different rates of expansion/contraction? It sounds like I stumbled on another opportunity to learn something practical.

Darrel Hood
DILIGENT PROPERTY SERVICES

Jerry Peck
11-10-2008, 07:02 PM
In the cases of stucco directly on concrete, how do they allow for the different rates of expansion/contraction?

Darrel,

They are basically about the same, not to mention that, when applied properly, they become one and the same.

Unlike stucco over frame, brick veneer over frame, etc., the stucco bonds directly to the concrete block on the minute mechanical level (stucco grabs into the pours of the concrete block) making them basically one and the same. When doing a core sample, you can see where the stucco bonds with, and blends in with, the concrete block.

With poured concrete, the surface is much smoother than concrete block is, making that mechanical bond very limited, requiring a bonding agent which mechanically and chemically 'glues' itself to the concrete and to which the stucco mechanically and chemically bonds.

Being 'one substrate', they expand and contract together. Also, both being portland cement based, they have very similar expansion and contraction coefficients.