flat roof commercial mounting.

[Energetic]

We're quoting on our first flat roof commercial system, looking for recommendations as to the simplest install, least ballast, best looking etc...

Not yet come across any that make you think 'wow that's the best!'

 

[SibertSolar]

K2 or Avasco low-ballast mounting solutions are worth considering, feel free to drop me a PM if you would like to discuss. Hope this helps, other options are available I'm sure

 

[Worcester]

What's the roof construction? and What is the covering material?
What is the actual slope (some roofs are 'flatter' than others )
How 'low ballast does it need to be?
What's your criteria - speed of install? minimum ballast? cost of mounting system?
I've lost count of the number of flat roofs we've done using numerous different mounting systems.

 

[SpitfireW'sale]

It can be tricky to get this right. One of the main issues is the height of the building. Most mounting systems require greater distance from the roof edge to the first row of modules as building height increases. There is a definite gap in the market for a cost effective anchoring system especially on new build commercial projects. I'll be interested to see what people use for this as we are always looking for good solutions in this area!

 

[Worcester]

@Spitfire, as a rule of thumb that zone is H/2 (i.e half the height of the building away from the edge) meaning tall buildings have a problem; low, wide and long buildings not usually an issue.

 

[SpitfireW'sale]

Thanks, yes I understand that, hence the height of the buiilding being the main issue

We design many systems for commercial installers and M&E contractors for new builds. Many of them are simply not viable systems as the building is say, 20m tall and you can only get a few modules on the roof if manufacturers guidelines are adhered to. We have created solutions to "make it fit", but none of them are particularly pretty, cost effective or simple to install. They also need structural calc's and wind loading done which adds huge amounts to the cost.

The solution needs to come from architects designing buildings that have given thought to how PV is installed, with anchoring systems or similar designed into the roofing fabric to facilitate easy installation. The lack of process in the design phase of a commercial building for PV (despite it effectively being a requirement on new builds), surprises me. Retrofitting ballasted systems or any other alternative onto a new build flat roof seems very inefficient to me and yet this is the norm, hence my belief that a gap in the market exists for a solution in this area.

 

[Energetic]

Thanks for the ideas, interesting first site visit today, the flat roof is neither flat nor flat.

The ridge is running N-S so we have two very low angled E/W inclines. Roof is sheet metal sandwich with fiberglass infill and standing ridges around 50mm high. Ideally we're after zero penetration but but open to suggestions.

 

[SpitfireW'sale]

Looks like trapezoidal section. Usual solutions for that are Metasole from Renusol (we stock this and happy to price) or Speedrail from K2. I believe Metasole is the most cost effective, but the Speedrail system gets good reviews. Both systems have very effective means of stopping any water ingress so you shouldn't be too concerned with penetration. If you have not used Metasole before then we can organise a representative from Renusol to attend site with you on day 1 to assist with marking out. We can provide documentation, technical support, bill of materials etc.

If you have to riase the modules up to a higher pitch (it looks like you might) then you need to provide details of the sub structure. It is possible to do this and if you are in the Midlands any time soon you're welcome to see a 50kW install on a similar roof on top of our warehouse. This is on trapezoidal section on an E/W roof with modules raised up to 30 degrees on Aluminium framework that we fabricated to face South.

Hope that is some help.

 

[Worcester]

That's a secret fix roof.

You wont get away ballasted as there won't be enough sliding resistance, it will have to be anchored to the roof.

You'll need to get between the layers (yes I know it will be difficult we have to do it all the time ) and identify exactly how the top section is fixed and wether those fisings are strong enough, calcs will be needed.

If the roof fixing is strong enough, then using any of the A-frame from K2, schletter etc should work. (You may need the wind baffles installed on the rear especially if they are installed portrait. If it isn't, you might have to do what we did on one job and put 5,000 double thread tek screws from the top covering into the underlying purlins. like these:
Tek screws, drywall screws, collated screws, and light anchors from Evolution Fasteners.
Tek screws, drywall screws, collated screws, and light anchors from Evolution Fasteners.
they need to be bi-metal (stainless steel and hss point) and they don't come cheap.
and then you can use one of tthe non-ballasted A-frames.

Whichever method you choose, you will need a structural anaylis on the fixing methodology including the structural integrity of the roof covering.