Hello everyone,
I have an important question regarding the following.
I am receiving precast concrete walls for my basement. For waterproofing, a membrane was applied around the perimeter of the floor slab, extending about 15cm (6 inches) beyond the slab edge. At one spot, this membrane is completely damaged.
My question is how should I proceed? Is this a minor issue or something more serious? Also, is the waterproofing installed incorrectly, since shouldn’t the adhesive side face outward rather than inward?
I would appreciate your knowledge and advice.
I have an important question regarding the following.
I am receiving precast concrete walls for my basement. For waterproofing, a membrane was applied around the perimeter of the floor slab, extending about 15cm (6 inches) beyond the slab edge. At one spot, this membrane is completely damaged.
My question is how should I proceed? Is this a minor issue or something more serious? Also, is the waterproofing installed incorrectly, since shouldn’t the adhesive side face outward rather than inward?
I would appreciate your knowledge and advice.
Good morning,
just a quick note:
No membrane was installed; instead, a coated joint flashing was used. The membrane on top serves to protect against contamination and weathering of the coating (likely bituminous).
The membrane will be removed before the wall is concreted.
The black coating should be present on both sides of the flashing. If the membrane has already come off in some areas, that is not a problem.
Regarding the damaged area:
I cannot quite tell if the area is actually damaged or if it is a joint that was not properly executed.
In either case, this is not acceptable and must be corrected urgently.
There are manufacturer specifications for the overlap length at joints that must be strictly followed.
I would forward this defect to the construction company and have them confirm that they have fixed it.
Feel free to show me the repair work once it’s done so I can provide my feedback.
Furthermore, it appears that the flashing was attached directly to the protruding reinforcing bars.
Is that the case? Or is there a gap between the flashing and the rebar? Please send a photo if possible.
In general, the waterproofing must not be in direct contact with the reinforcement.
To prevent this, flashing is usually secured with so-called OMEGA clamps. I don’t see any here; it looks like wire ties were used instead.
If you find any joints in the flashing, please also send a photo. These must also be secured with special clamps.
Best regards,
Jann
just a quick note:
No membrane was installed; instead, a coated joint flashing was used. The membrane on top serves to protect against contamination and weathering of the coating (likely bituminous).
The membrane will be removed before the wall is concreted.
The black coating should be present on both sides of the flashing. If the membrane has already come off in some areas, that is not a problem.
Regarding the damaged area:
I cannot quite tell if the area is actually damaged or if it is a joint that was not properly executed.
In either case, this is not acceptable and must be corrected urgently.
There are manufacturer specifications for the overlap length at joints that must be strictly followed.
I would forward this defect to the construction company and have them confirm that they have fixed it.
Feel free to show me the repair work once it’s done so I can provide my feedback.
Furthermore, it appears that the flashing was attached directly to the protruding reinforcing bars.
Is that the case? Or is there a gap between the flashing and the rebar? Please send a photo if possible.
In general, the waterproofing must not be in direct contact with the reinforcement.
To prevent this, flashing is usually secured with so-called OMEGA clamps. I don’t see any here; it looks like wire ties were used instead.
If you find any joints in the flashing, please also send a photo. These must also be secured with special clamps.
Best regards,
Jann
Hello Mete,
Thank you for the pictures.
Do you also have photos of the areas where the metal sheets are joined or overlapped?
I’m not allowed to send links, but you can search for Pentaflex KB on Google — there are good images showing how it is installed.
Although your product is different, they are generally installed in a similar way.
If you find out the product name (usually it is printed on the membrane), feel free to let me know.
In any case, you should point out the incorrect installation of the metal sheet to your builder, so that if any damage occurs later—which is not necessarily the case—they remain covered under the warranty.
If you provide me with the details, I can gladly draft a message for you.
Thank you for the pictures.
Do you also have photos of the areas where the metal sheets are joined or overlapped?
I’m not allowed to send links, but you can search for Pentaflex KB on Google — there are good images showing how it is installed.
Although your product is different, they are generally installed in a similar way.
If you find out the product name (usually it is printed on the membrane), feel free to let me know.
In any case, you should point out the incorrect installation of the metal sheet to your builder, so that if any damage occurs later—which is not necessarily the case—they remain covered under the warranty.
If you provide me with the details, I can gladly draft a message for you.
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