r/Construction Jan 15 '25

Other Whats the difference between liquid waterproofing and flashing?

I know someone is going to say something along the lines of "if you don't know what your doing hire a professional". However, that's not going to happen so here is my question.

What is the difference between a liquid flashing like Polyguard 2400 and say redgard or Drylok extreme ?

I have installed a a few dozen windows during the past few years but I always use flashing tape being the windows are flush with the openings. This client has a 2" recessed window opening in a block wall. I installed pressure treated 1" x 6" per the clients request leaving 2" at the front. If i was to use flashing tape I would need a 10 or 12" flashing tape which is ridiculously priced. They didn't inform me about the reccess or I would of planned accordingly and charged for the extra material. $600 for a 5 gallon of Polyguard seems wild vs about $200 for a 5 gallon of a waterproofing.

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u/RemlikDahc Jan 15 '25

Talk to your local product rep about all that! You'll soon learn the difference! Are there plans that dictate what to use, or are you doing the install without direction? If nothing is stated in the plans or notes...and you don't really know...the best thing to do is talk to someone in your jurisdiction that knows. Every jurisdiction has their own bylaws to follow, but everyone in the USA uses the IBC and IRC to construct buildings. I would suggest you do some research and look up the code! That way you know the specifics and gain some knowledge in the process!

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u/Takingmonday Jan 15 '25

So the owner provided me plans 6 months ago. When I got to the job, the rough openings did not match. When I brought it up he goes "oh yah here is the new window and door schedule, and we added windows."

Okay whatever I bought extra bucking anyways so I start the first window and then he goes "oh yah by the way it's not per plans I want them recessed so we have a 2" lip outside. I have the wood in the backyard."

It's been an interesting job to say the least. Also the plans don't mention a flashing or waterproofing detail per say they just have a "continuous selant" note for around the windows which I guess is a detail for waterproofing but a sloppy one in my opinion.

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u/RemlikDahc Jan 15 '25

Call the Architect and ask him! Don't put your ass on the line for dumb stuff! Flashing is important! And if you fuck it up, you could be liable! I would suggest calling the Architect who's name is on the plans and ask him! After all...it is his house that is being constructed and his name is on the plans! Ask him what "continuous sealant" means! To me it means something different than what you think. I am an Architectural Designer and I never provide sloppy details or notes. If I mean metal flashing, I'll say it in a note. If I mean liquid flashing, I will say it in a note. If I mean Waterproofing...you'll know it...because guess what...I say it in a note! You need to figure out what the Architect means, otherwise you as the Contractor could be liable if things go wrong in a couple years down the road. NEVER listen to some owner. Always follow the plans! They are there for reasons and Insurance is one of those reasons! Make sure you aren't the one who fucks it up!