Problem with cracks both internally and externally in house built with Porotherm blocks

[enjoy]

We feel that we need expertise on how we should/proceed with our house, which we built 5½ years ago, and since then it has been cracking more and more both on the facade and on the interior walls of the house. The house is built with Porotherm blocks from Wienerberger and has a plastered facade and plastered/spackled interior walls.

The builder has been on site and noted the cracks, we have had Wienerberger come and look, and have had two inspections where this has been pointed out, but still, no one wants to address it. The builder repaired all the cracks in the facade after the two-year inspection, but just a few months later they started to appear again and new cracks are still constantly emerging. Most of the time, they can be traced back to "following" the blocks.
The cracks inside usually begin as small shrinkage cracks and then "shoot off" like a glass fracture and spread both vertically and horizontally. Now it’s even so that some cracks have become so large that the wall is no longer flat when you feel over the crack.

Is there anyone else who has experienced something similar with these blocks? We have heard of a larger construction with the same issues, but unfortunately, we don't have the whole background other than it should be somewhere out in Österlen.

How should we proceed? Who do we turn to? Can legal assistance be obtained in some way?

Grateful for any tips!

 

[Alko]

Now, I have no knowledge whatsoever regarding issues that may arise with these cavity bricks, as I understand the matter concerns. But one wonders if the right mortar was used (or dryfix foam?), or if there are problems with ground vibrations or poorer load-bearing capacity under part of the foundation causing settling. Are the cracks evenly distributed over the facade? A picture of the facade could help, but it does seem like one should focus on clarifying the question of responsibility, as it doesn’t sound like a process (the cracking) that is easy to stop anyway.

Maybe it should be posted in the legal forum?

/A

 

[Mainstream]

How have you reinforced the plaster? How is the foundation built? Does the execution match the drawings? The walls are moving, so the plaster must be able to handle it.

Today, it is recommended to net the entire surface to avoid cracks.

 

[isolde]

Without seeing the house, one can start with the method of elimination. Check off:

- mortar for the blocks (mixing ratios/type/foundation)
- reinforcement bars between courses
- reinforcing mesh

Did you begin to notice cracks two years after the construction of the house?
If the above points are checked off, I suspect a weak slab on grade. For some reason, constructors often skimp on reinforcement and often settle for just three lower reinforcement bars in the footing. If you consider the footing as a beam and calculate that it may be subjected to bending moment up or down, you realize that top reinforcement is equally important. That is, footings should be reinforced both at the bottom and top. The corners of the house can either settle or do the opposite.

Are the cracks on certain walls, or on all? On load-bearing walls, or also on partition walls? Cracks near door and window openings?

 

[Stefan N]

It's being built with thin joint mortar, so reinforcement isn't used, right? They don't prescribe any mesh for the plaster either, as far as I remember.

 

[isolde]

It's built with thin joint mortar so reinforcement isn't used, right? They don't specify any mesh for the plaster either, as far as I remember.

Yes, indeed. It should be reinforced, especially under and above window openings. There are different types of reinforcement bars. Standard ribbed steel can be used in lightweight concrete as grooves can easily be milled into it. For Porotherm, there is a flat variant available.

Plaster should always be meshed. It doesn't have to be steel mesh but can be fiberglass mesh for thin plaster (exterior), which can also be advantageously used indoors for gypsum plaster.

 

[KW78]

Hi! We have exactly the same problem that you describe and have also built with porotherm. The house is exactly a few years old and we have continuously addressed cracks, but new ones keep appearing. How have you proceeded? Have you found any solution?

 

[moperandi]

I find it hard to believe that there would be problems with the blocks themselves. Virtually all houses here in Bavaria where I live are built with Porotherm blocks (or Poroton as they are called here), and I have neither seen nor heard of such problems.

 

[KW78]

According to the builder, there were errors in the plaster recommendations.

 

[KW78]

According to the builder, there was an error in the plaster recommendations.

Have you made any progress with this? We have exactly the same problem and the builder claims an error in the plaster recommendations. Reported to Garo but they do not cover the damage.

 

[Apex11]

We feel that we need expertise on how we should proceed with our house that we had built 5½ years ago, which has since then been cracking more and more both on the facade and on the interior walls of the house. The house is built with Porotherm blocks from Wienerberger and then rendered facade and plastered/spackled interior walls.

The builder has been on site and observed the cracks, we have had Wienerberger come and look, had two inspections where this was pointed out but still no one wants to address it. The builder repaired all the cracks in the facade after the two-year inspection but already a few months later they began to crack again and new cracks are constantly appearing. Most of the time they can be traced to "follow" the blocks. The cracks inside usually start as smaller shrinkage cracks and then "run away" like a glass break, expanding both vertically and horizontally. Now it's even to the point where some cracks have become so large that the wall is no longer flat when you feel over the crack.

Is there anyone else who has experienced anything similar with these blocks? We have heard of a larger construction with the same problem, but unfortunately do not have the full background other than that it should be somewhere in Österlen.

How should we proceed? Who do we turn to? Can we get legal assistance in some way?

Grateful for any tips!

Have you made any progress with this? We have exactly the same problem and the builder claims errors in the rendering recommendations. Have reported to Garo but they do not cover the damage.

How has it gone for you?

 

[Anto Katinic]

We feel that we need expertise on how we should/proceed with our house that we had built 5½ years ago, which has increasingly developed cracks both on the facade and on the interior walls. The house is built with Porotherm blocks from Wienerberger and then plastered facade as well as plastered/wide-spackled interior walls.

The builder has been on-site and noted the cracks, we've had Wienerberger come and take a look, had two inspections where this was pointed out but still, no one wants to address it.
The builder repaired all cracks in the facade after the two-year inspection, but just a few months later they started to crack again, and new cracks are constantly appearing. Often, they can be traced back to "following" the blocks.
The cracks inside usually start as minor shrinkage cracks and "run away" like bullet marks, spreading both vertically and horizontally.
Now it's even to the point where some cracks have become so large that the wall is no longer flat when you feel over the crack.

Is there anyone else who has experienced anything similar with these blocks? We have heard of a larger building with the same problem, but unfortunately, we don't have the full background other than that it should be somewhere out on Österlen.

How should we proceed? Who do we turn to? Can we get legal help in some way?

Grateful for any tips!

Hello,
I built a house in Limhamn 15 years ago with Porotherm blocks and I have no problems with cracks anywhere.
We used mesh and thick plaster and cast all load-bearing beams with reinforcement bars.
You have probably made a mistake in execution or used the wrong materials.
Best regards, Anto