Roof Stack Access with A-Mezz Catwalks and Ladders

A company contacted us because they needed safe roof stack access. The EPA required them  to do regular tests on their stacks to comply with the Clean Air Act, but they had no permanent, safe means of access.

 

When we went out to the site for a preliminary review, accessing their stack was no easy feat. We needed to use a lower extension ladder to reach the lowest roof and bring up another extension ladder to use on the lower roof to access the middle roof.

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To make matters worse, once we were on the middle roof, it wasn’t made with regular foot traffic in mind. We had to constantly be mindful of our step. Each metal roof panel groaned and flexed with each precarious step we took. Our goal was to keep the solution simple. It gets really easy to over-engineer a solution, but all that does is increase costs while not always providing a better product for the conditions.

What Were Our Options?

Our first thought was to have a fixed ladder extend from the lower roof to the middle roof, similar to their existing lower to upper caged ladder. We decided against that for a couple of reasons.  The first was that there was no back wall to mount a walk-thru ladder. This would make us need to increase materials and engineering time, creating a custom solution which would just add costs to the project. Another option was for mounting a ladder on the same wall as their existing ladder and having it exit onto the side. We chose against this because the exit location was far from the stack needing access and that would have greatly increased the size of the catwalk needed, thus increasing costs.

Fixed ladder from upper roof to middle roof for roof stack access

Fixed ladder from upper roof to middle roof for roof stack access

An Economical Solution

We decided that the best solution was to utilize their existing ladder from the lower to upper roof. We then would fabricate a ladder to access the mid roof from the upper roof, as they would already have a need to be on the upper roof to inspect stacks there. The upper roof had a low parapet that the client didn’t want people stepping on. Our fixed ladder had a step-across platform incorporated into it so their workers could step onto that instead of the parapet, allowing for safer access to the ladder while protecting the parapet flashing.

Our installed roof stack ladder and catwalk provides safe access under customer's budget

Our installed roof stack ladder and catwalk provides safe access under customer’s budget

We also fabricated a short catwalk and platform surrounding their stack. We designed the framing for the platform to mount onto their existing purlins with elongated supports as the platform extended to compensate for the roof slope. This allowed for a level, safe platform for their testing team to work from, eliminating the fear of slips in inclimate weather that can come from an iced up, sloped catwalk system. 

A Quick, Permanent Roof Stack Access Solution – Under Budget

Ultimately, we relocated the access ladder from original plans which allowed us to utilize our mostly standard ladder design. The location change also allowed for a smaller platform which allowed us to complete the project under the customer’s budget. This project took 9 weeks from the date we got approval drawings in the customer’s hands to the completion of installation.

Using the Roof of a Modular Office for Storage

office with storage above

The main purpose of the roof deck in a modular building is to form a membrane that holds the whole system together. Due to cost considerations, we typically design them with enough load capacity to support the lights and acoustical ceiling.  That doesn’t always have to be the case though. We can also design it so that the roof of your building can be used for light storage. I recently got some photos back on a project where the customer wanted to do just that.

top view

It was a pretty cluttered area, so hopefully the load bearing roof will give them some breathing room.

The customer wanted to put in an office for the maintenance manager and his team in order to cut down on the noise.  The corner of the facility where they were situated was already pretty cluttered and they didn’t want to lose any more space back there, so they came to us in hopes of putting in a modular office with enough load capacity on the roof to use it for long-term light storage.

interior wall with reception window

The sliding reception window allows the employees to easily communicate between offices.

The office was 20′ wide by 12′ deep.  They wanted to break it into two separate 10’x12′ offices, but they wanted to make it easy to communicate between offices, so we put in an internal partition wall with a sliding reception window.  

recessed beam hangers

Modular wall panels with structural connectors and hangers to support the recessed beams.

There were a few things we needed to do in order to support a 100 PSF live load on the deck. We needed to put 10″ c-sections spanning from the front to the back of the building attached to hangers in the ceiling plenum.  To support these c-sections, we used structural panel connectors between our wall panels as opposed to our typical tongue and groove or I-spline connections. While we could have gone with a 2-wall system due to the modular office’s location in the corner, we put a third wall along the back to support the c-sections instead of dropping columns to save the customer a little money as well.  Due to the size of the recessed c-sections we went with 9′ tall panels so the customer could maintain a 8′ clearance height in the room.

beam in the ceiling

A structural c-section was recessed into the ceiling plenum at every panel connection.

There were a few things we needed to do on top of the deck as well to finish it off.  We covered the corrugated roof deck with OSB so that the customer would have a smooth walking surface above.  We also fabricated and installed some surface mounted handrail and kick plate, as well as a spring loaded access gate to keep their workers from falling off the edge when moving around on the roof.  You would also need to put in a staircase to access the system, but the customer told us they were going to take care of their own egress.

looking onto the load bearing roof

The surface mounted handrail will help keep workers safe when moving around on top of the office

The system went together nice and quick.  Mechanical and electrical installation took a little less than a week, and the customer was really pleased with his new office. Now they just need to start moving things to the roof.