Hello,
We are currently building a new house (KfW40 standard) with exterior walls made of aerated concrete blocks (17.5cm (7 inches)) that will later be clad with brick veneer after insulation is installed. In several places where cut aerated concrete blocks meet, relatively wide joints (about 1cm (0.4 inches)) have formed, which are still open at the moment. The site manager does not see this as a problem. The gaps are planned to be filled with mortar on the outside and sealed airtight on the inside by plastering.
Is the presence of such joints already considered a defect, or is this acceptable? Will the insulation be affected by these joints? Is the planned method of sealing proper, or should it be done differently?
Thank you very much!
We are currently building a new house (KfW40 standard) with exterior walls made of aerated concrete blocks (17.5cm (7 inches)) that will later be clad with brick veneer after insulation is installed. In several places where cut aerated concrete blocks meet, relatively wide joints (about 1cm (0.4 inches)) have formed, which are still open at the moment. The site manager does not see this as a problem. The gaps are planned to be filled with mortar on the outside and sealed airtight on the inside by plastering.
Is the presence of such joints already considered a defect, or is this acceptable? Will the insulation be affected by these joints? Is the planned method of sealing proper, or should it be done differently?
Thank you very much!
B
Bieber081514 Nov 2016 15:27The butt joints should not be wider than 3 mm (0.12 inches) and do not need to be filled with mortar. Butt joints wider than 5 mm (0.20 inches) must be sealed with appropriate mortar.
B
Bauexperte14 Nov 2016 19:05deichwacht schrieb:
Is the presence of such joints already considered a defect, or is it unproblematic? Does this affect the insulation? Is the planned method for sealing it correct, or should it be done differently? Masons are not precision technicians! Relax.
Your site manager has explained the correct procedure to you—why don’t you trust him?
Regards, Bauexperte
Bauexperte
S
Sparstrumpf14 Nov 2016 21:25Do these butt joints still need to be filled with any material, or is plastering on the inside and outside sufficient? Today, we also noticed several spots with these joints and at first thought it might be poor workmanship—just amateurs, really.