foundation pins puncturing my membrane

[concrete4gent]

I just had my foundation waterproofed with a Mar flex spray and dimple board. it looks great, but I’m losing sleep over the installation. the crew used a Ramset gun to pin the board, which means they blasted holes right through the monolithic membrane.

worse, some pins failed when they hit aggregate, chipping the concrete behind the board. The installer says it’s normal and that the pins self seal or won't leak because the membrane stays tight, but I’m worried I’ve just paid for a sieve

should I be peeling back the board to patch those chips or just let it be?

 

[purriitttooo]

Usually thereis still enough coating left to keep everything sealed and dry after the soil is packed in.

 

[last goodbye]

I just had my foundation waterproofed with a Mar flex spray and dimple board. it looks great, but I’m losing sleep over the installation. the crew used a Ramset gun to pin the board, which means they blasted holes right through the monolithic membrane.

worse, some pins failed when they hit aggregate, chipping the concrete behind the board. The installer says it’s normal and that the pins self seal or won't leak because the membrane stays tight, but I’m worried I’ve just paid for a sieve

should I be peeling back the board to patch those chips or just let it be?

The spray coating is made to be thick and flexible. When the pin goes in it wraps around it and keeps moisture out.

 

[Alan]

Well, a shattered aggregate "blowout" can compromise the monolithic seal but most professionals don't advise peeling the board back. The hydrostatic pressure of the backfill usually keeps the dimple board tight against the membrane to divert water away from the pins. So you should only intervene if you observe active moisture around the fasteners from the interior of the foundation. Hope that helps.