Dry floodproofing metal building
Dry floodproofing metal building
(OP)
I've been asked to design the dry floodproofing measures for a non-residential pole building with 29 gauge metal siding. The owner does not want to elevate the building above the flood elevation, hence the floodproofing.
As I understand it, dry floodproofing the building would involve:
1) Ensuring that the building is securely anchored to resist floation, collapse, and lateral movement.
2) Installation of some kind of flood barriers on building openings (doors, windows).
3) Reinforcement of walls to resist floodwater pressures as well as impact forces from floating debris.
4) Use of membranes and/or sealants to prevent seepage through walls.
Anyone out there have experience dry floodproofing a building of this type? I've found most of the FEMA documents that pertain to floodproofing, but I was hoping someone might be able relate some actual experiences with this type of job. Specifically, what would work best for sealing the walls?
Thanks,
Cap
As I understand it, dry floodproofing the building would involve:
1) Ensuring that the building is securely anchored to resist floation, collapse, and lateral movement.
2) Installation of some kind of flood barriers on building openings (doors, windows).
3) Reinforcement of walls to resist floodwater pressures as well as impact forces from floating debris.
4) Use of membranes and/or sealants to prevent seepage through walls.
Anyone out there have experience dry floodproofing a building of this type? I've found most of the FEMA documents that pertain to floodproofing, but I was hoping someone might be able relate some actual experiences with this type of job. Specifically, what would work best for sealing the walls?
Thanks,
Cap






RE: Dry floodproofing metal building
Build a kneewall to above the flood elevation, then start your metal panels. You can waterproof the kneewall in a variety of ways.
RE: Dry floodproofing metal building
Thanks for your reply... by kneewall do you mean a short concrete stem wall, or a wood framed wall? If the latter, what methods are best for floodproofing?
Thanks again for your help.
RE: Dry floodproofing metal building
RE: Dry floodproofing metal building
Thanks for your reply, that's makes sense to me.
The client wants to do a pole building (see the attached jpeg). But if I recommend that he goes with a concrete kneewall, could he still do a pole building (just encase the posts up to the top of the stemwall)? I've never seen that done with a pole building... but I've never designed one that's located in a floodplain either.
Thanks again.
RE: Dry floodproofing metal building
He is still going to have to sandbag his doors and have a sump pump and generator on hand too. Just a fact of life. Might want to consider constructing some upstream debris barriers too.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dry floodproofing metal building
Cap07...encasing the poles in concrete should only be done if you coat them with an asphalt mastic. If you are depending on the embedment for moment resistance, then you'll have to consider that in your design. Otherwise, provide a pier in the kneewall and use a bolted connection for the poles to the concrete. You'll need knee braces at the top of the pole for lateral stability if you choose this route.
RE: Dry floodproofing metal building
Ron - The client originally wanted to do a pole building, so I was planning on using the poles for moment resistance. Please see the jpeg I attached in my third post. Would it make sense to still embed the posts down 4', with the concrete knee wall beginning at a higher elevation, e.g. 1' below grade (whatever is required for frost and scouring protection)?
Thanks.
RE: Dry floodproofing metal building
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dry floodproofing metal building
Cap07..yes, you can embed and then encapsulate the poles with the wall at a higher elevation or just inset the poles inside the wall and create an insolation joint at the floor slab, with provisions of waterproofing the joint for hydrostatic pressure during the flood event. The flashing from the wall panels should extend over the top of the wall if you inset the poles.
RE: Dry floodproofing metal building
Ron - Thanks also for your suggestions and comments.
You guys have been very helpful - thank you for all of your suggestions, etc.!
RE: Dry floodproofing metal building
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dry floodproofing metal building
Around here, they put flood vents at the floor level. With an impending flood - they move everything out. Some people open all the doors. The vents allow the water to come in - do little if any damge and drain out. Hose it out and move back in.
Of course - this idea offers little resistance to debris damage. But 29 gauge metal is really quite cheap. If you only have to do it once in awhile...
RE: Dry floodproofing metal building
Michael.
Timing has a lot to do with the outcome of a rain dance.