We have a “butt-jointed” masonry wall (Bim thermally insulating hollow block bricks), which sometimes has larger vertical open joints! Furthermore, the joints are mortared but unfortunately not to the full depth of the brick. That means with bricks 30 cm (12 inches) thick, only 29 cm (11.4 inches) are mortared. On the outside, 1 cm (0.4 inches) is missing. Now the quiz question: The house will be plastered. A thermal insulation plaster of only 3 cm (1.2 inches) thickness is planned. I have read that in the case of improperly mortared masonry, there is a risk that the joints may later visibly show through the plaster when wet. Is this true? Apart from that, the stability of the masonry might also be compromised if the joints are not properly filled!
Which regulations apply here? DIN standards? Regarding joint mortaring (width and depth). The building permit / planning permission was submitted after February 2002, so the house is subject to the energy saving ordinance.
Thanks for your answers!
Which regulations apply here? DIN standards? Regarding joint mortaring (width and depth). The building permit / planning permission was submitted after February 2002, so the house is subject to the energy saving ordinance.
Thanks for your answers!
?? (Bim. thermal insulating hollow blocks) ??
They should be fully filled with mortar! This is the most important requirement for a suitable base for plastering. If the joints are slightly recessed, they not only look unattractive, but plaster will also crack exactly at those spots because the plaster layer then varies significantly in thickness. For example, 40mm (1.6 inches) in one area instead of 30mm (1.2 inches) in another. Due to drying times differing with thickness, the thicker plaster over the joints shrinks more than the plaster on the surface. The result - cracks!
The joints must also be repaired before starting the plastering work. This should be done well in advance to allow the masonry mortar to dry completely before plastering begins!
Whether the vertical joints must be fully and evenly filled with mortar?
The structural stability is probably not at risk because of these deficiencies... I am not aware of any further requirements regarding this for "Bim. thermal insulating hollow blocks," as these are no longer used in our region...
They should be fully filled with mortar! This is the most important requirement for a suitable base for plastering. If the joints are slightly recessed, they not only look unattractive, but plaster will also crack exactly at those spots because the plaster layer then varies significantly in thickness. For example, 40mm (1.6 inches) in one area instead of 30mm (1.2 inches) in another. Due to drying times differing with thickness, the thicker plaster over the joints shrinks more than the plaster on the surface. The result - cracks!
The joints must also be repaired before starting the plastering work. This should be done well in advance to allow the masonry mortar to dry completely before plastering begins!
Whether the vertical joints must be fully and evenly filled with mortar?
The structural stability is probably not at risk because of these deficiencies... I am not aware of any further requirements regarding this for "Bim. thermal insulating hollow blocks," as these are no longer used in our region...
M
Mauer-Fred2 Jan 2008 02:03Joint Width/Depth in Masonry
Hello,
Every, and I mean every, proper mason definitely ensures there are no open bed joints or head joints. That really should be a given!
If your walls were built like this, I would recommend raising a complaint with the wall manufacturer, meaning the construction company, and withholding payment until all joints have been properly filled, and crucially, before any plastering is done!
Of course, there is a relevant standard for this: DIN 1053. But unfortunately, there seem to be more and more “wannabe” masons who really don’t understand masonry! And apparently, some construction companies dare to deliver such walls to their clients!
Building can sometimes be a bit disappointing.
Hello,
Every, and I mean every, proper mason definitely ensures there are no open bed joints or head joints. That really should be a given!
If your walls were built like this, I would recommend raising a complaint with the wall manufacturer, meaning the construction company, and withholding payment until all joints have been properly filled, and crucially, before any plastering is done!
Of course, there is a relevant standard for this: DIN 1053. But unfortunately, there seem to be more and more “wannabe” masons who really don’t understand masonry! And apparently, some construction companies dare to deliver such walls to their clients!
Building can sometimes be a bit disappointing.
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