So as you may know, I am a real estate baron.....

Bad part of my job requires me to rehab properties I have foreclosed on before put them back up for sale. I am the proud "property manager" for 4 such properties. Thankfully I have received some great help from a number of friends and family getting a few of these properties ready.

This leads us to our current project, a defunct car wash in Hoquiam. Concrete block structure, "I" and "box" beam steel structure overhead holding everything together. We have an abatement order from the city to take the roof off. Roof is interlocking panels, roughly 28' long, and instead of screwing these panels down, they decided to spot weld (probably with a wire feed) these panels along the "I" and box beam structure two feet from either end, and in the center along the center "I" beam. Getting the southern leading edge secton off isn't an issue, as the weather comes from the SW, and being Hoquiam, that means salt air. This means that the way they attached the roof failed first here.

They attached the roofing panels as such. Panels were layed across the steel structure, and then they placed something like cut washers on the panels directly on top of the "I" beam. They then ran the wirefeed filling in the center portion of the washers.

What is the most expediant way of getting the steel panel to release from the "I" beam at the spot weld? Sawzall blades worked well, but we went through 8 or so, and the time it took slowed us down. Cost isn't an issue on blades, as bank covers time & materials + equipment repairs, but if we could just rip through the project in 20 hours with 3 guys, that would be great. Two guys working for 6 hours got off about 1/4 of the roof. I have my Acet/Oxy torch, but I don't want to damage the "I" beams. We are working on ladders 14+ feet in the air, which isn't an issue for us for as far as heights, but leverage can be an issue, working on a ladder that high up. We have a generator, power, and just about every tool known to general contractor.

Suggestions? There has got to be a faster way.

Thanks in advance!

Rent a plasma cutter.

If all you need to cut through is a spot weld get a spot weld cutting bit. Matco and snap on sell them I know. I have the matco set.
They work well in high speed right angle grinders.

110 or 220?

or do this but I'm guessing you don't have 220V on site.

Pneumatic chisel?

Hard to visualize what you are up against, but a spot weld can usually be broken with a cold chisel.

Put a "Roof Panels For Sale" sign out for the Tweakers to see, they'll steal it the 1st night...Buddy got rid of his broken chest freezer 1st night he set it out "for sale"... or try peanut grinder on those welds ...

This makes more sense.

Those are called "puddle welds" and they were part of the roof diagram.
Sounds like those washers were used because the steel decking gauge was too thin to meet whatever uplift calc the engineer had to use.

It's unusual to see washers used like that.
Any pics ?

So these puddle welds are probably in every down flute ?

Without seeing a pic, I would want to destroy the washer and the decking while leaving most of the puddle weld.
Cutting between the beam and decking with a Sawzall sounds brutal.

I would lean more toward a peanut grinder (4-5") or even a 7" with a metal stone to go after the washer/weld.
It would be extremely useful to have a scissor lift, 1.) For the safety of working off of and 2.) To utilize its uplift power to push up on the deck panels after the welds were weakened.

A short 2x4 or 4x4 post from the scissor deck to the roof panel would be how to apply some push to the decking.
A gas powered scissor lift has a big deck and has lots of power compared to a skinny electric scissor, if you have the room and ventilation.

Another useful tool would be an air chisel like you would see in a muffler shop to go after those washers.

Edit:
Not knowing how clean you need to get the beams, a faster method would be to take a peanut grinder with a cut-off disk and simply do a 4-sided cut around the washer/puddle weld. I think that this would be the fastest way to get the decking off, even if you had to come back and touch up the welds.


I swear grinders cause more injuries than anything else so make sure they know what they're doing.
If they hit the work wrong the grinder can walk onto the user.

Edit:
A tool that we use for cutting deck panels during install is what's referred to as a "Hot Saw". This is a chain saw motor fitted with a large circular Carborundum blade.
They are not for the uninitiated, especially on a roof but they make short work of cutting up pan decking.

Every once in a while a tool comes along and I say "Holy Schitt".
Just recently I used a good bunch of these metal-cutting in a Skil Saw.
They look like wood blades from a distance but they sail through steel beams....big schitt.....freakin' amazing.
Got 'em at the Depot and it seems that they were a Makita product.

These would be very good for cutting up the deck panels if necessary for handling.
I have never seen a better metal cutting for a Skil Saw.
They're almost unbelievable. Not cheap, magic costs money.

Tried chisel & hammer. Slow.

Andy,
Simple analysis from what you describe-- The metal deck also works as a shear diaphragm to take lateral wind/seismic loads to the CMU block walls. Be careful so that you don't damage the supporting steel, and the new deck can go back on with the connections designed to perform in the same manner....

I may be the proud owner of a 2000 GMC 3500 bucket truck by next weekend, so that would certainly aid us with leverage at height.

I entirely appreciate the structural well being of beams, which is why I am asking.
Excellent ideas.

Fumes are not an issue as this is entirely outside.

Depending on the welds I wonder if a 4" angle grinder may be the way to go. Hard to tell without seeing what you are up against.

Also the grinder would be the way to clean up the beam after the roofing was gone.

We have multiple "peanut" grinders. We'll gives those a shot as well.

Gas powered scissor lift.
Do your prep work beforehand and rent it for a day.

Jaws of life ?

Grab some metal-cutting stones and a big bunch of cut-off disks (you know, those thin ones)

Be careful with the thin cut off wheels as they don't react well to side pressure.

Roto hammer with a chisel bit? Set so it doesn't rotate, of course.

Doesn't need to be prepped for the next guy, so bumps, etc. can remain. Just have to get the roof off.