Flat roof mounts

SD_DRACULA

Anyone got experience with them, which is good/bad etc?

I don't like any of the ones with rocks/ballast, too heavy as it's a wood frame building and about 5 degrees slope

The finish is resin & fibre glass so I don't see why I can't screw the rails directly into the battens with a bunch of these https://midsummer.ie/buy/fastensolpitched/F-HB-WP ? And they seem adjustable too so I can change the angle a bit too

10-10-20

Hi ya, is that into a residential roof now or an out building? I wouldn't be a fan of perforating the external finish on any flat roof at all. Plus it seems to imply that these are for corrugated roofs rather than flat... ?

Bolts are suitable for fixing mounting rail to metal or corrugated cement roofs with wooden supports.

SD_DRACULA

Residential, I know they aren't bespoke made for such a roof but just thinking of what "could" work

Try the valk3box.

The other thread on ground mounts had links to valk systems

SD_DRACULA

Found this

https://www.nicholsonsts.com/articles/installing-solar-panels-on-grp-roofs/

which seems to be specially made for these types of roofs but I really doubt I will find stock in Ireland for it

SD_DRACULA

https://www.boards.ie/discussion/comment/122164244#Comment_122164244

This is crazy weight added to the roof, 120kg per panel so 720kg of just tiles plus another 120kg the panels. If it wasn't timber frame it would be ok and I'm sure if can take it of course but I wouldn't want the extra stress on the roof.

And these fibre glass roofs are also very smooth, I'd be worried the panels sliding off.

BobMcBob

I have a single ply membrane warm roof and emailed the manufacturer for a solution, they sent me the brochure,

Problem is I can't get a solar panel installer to use it ll, either they've not replied , or they want to use a ballast system, which I'm not sure would be great for the insulation. Also since I have 3 phase and want to use a DIY battery I am struggling to get it sorted

FATRA IFP Installation Instructions.pdf

10-10-20

https://www.boards.ie/discussion/comment/122216627#Comment_122216627

Unfortunately if the installers don't have certification or even faith in installing the product then they aren't likely to want to install it as they'll potentially be liable for any future leaks. Try contacting the manufacturer and see if they have approved installers in Ireland.

SD_DRACULA

https://www.boards.ie/discussion/comment/122216627#Comment_122216627

I actually quoted that system for myself and if you want a laugh here's the price:

I think 28 pieces is overkill, probably only need 12 realistically, 3 per rail times 4 rails, even then it's mad expensive.

Spoke to the roofer that laid down the roof down for me and he says the roof hanger bolts should be fine as long as they're screwed into the rafters, these ones https://catalogue.k2-systems.com/hanger-bolt-solidrail-m10/2000122

BobMcBob

That's good to see a quote, not so good on the price!

The hanger bolts look good, but the description states fibre cement roof. So no good to me, it was hard enough to get house insurance with my roof, I suspect that I would not be covered unless I used the proper system.

Looking at your quote I think I will have to start getting information on compressive loads on insulation and the weights of the ballast used

SD_DRACULA

https://www.boards.ie/discussion/comment/122217663#Comment_122217663

Think I had a look at the ballast/bricks option and it was basically adding 120kg per panel on top of the roof, + panel and mounting system weight, not a fan of that.

conor_mc

The ballast calculators are a bit over-engineered imo, certainly at 120kg per panel! wind deflection etc. can play a big part, so putting say east-west panels back to back in a tent shape is more streamlined than all panels facing the same direction with exposed undersides.

SD_DRACULA

https://www.boards.ie/discussion/comment/122224450#Comment_122224450

Let's not forget that grp roof is basically an ice ring in terms of slippery

conor_mc

Fair point. Wonder if there are other ways of increasing the coefficient of friction besides increasing ballast?

...Ghost...

I'll be installing 4-6 panels on a flat grp roof. Was also considering hanger bolts, but it I really wanted to avoid putting bolts through the fibreglass, I could look at running a couple of custom made metal rails from parapet to parapet. Do you have an outside the box method to mount panels without disturbing the fibreglass?

DC999

https://www.boards.ie/discussion/comment/122225048#Comment_122225048

Could you somehow brace the ballasts to the side wall off the house? That's assuming there is another storey of the house above the flat roof. Then you won't have holes in the flat roof, but would in the wall as you would for any other fixing like gutters, satellite dish….

SD_DRACULA

I was thinking that alright, a 3.6m rail would basically cover the width of the roof and maybe then I could come up to meet it with a vertical rail from where the fascia will be.

Problem I see that there is no support in the middle

(roof not painted yet just resin)

The K2 rail system also has climber rails so could make a box out of them, run the rails in landscape and portrait and then panels on top.

I did a test with one of the hanger bolts, through an osb sheet and it makes a very nice seal I must say, pilot hole of 7mm through the rafter and 14mm through the osb (though it wouldn't hurt to fill it with silicone as well)

bunderoon

https://www.boards.ie/discussion/comment/122228290#Comment_122228290

41mm x 41mm Unistrut is very strong and has loads of configurations. If you have an angle grinder with cutting disk, you could make two trusses.

SD_DRACULA

I think I might do the following which should do it (in theory)

Run 3 rails across first, the red squares are where the hanger bolts will be which sit outside of the room below.

Then use 4 climber rails vertically on which the panels will bolt into, pray 🙏

slave1

https://www.boards.ie/discussion/comment/122228290#Comment_122228290

If you're doing that you could create a tilt versus having flat

SD_DRACULA

https://www.boards.ie/discussion/comment/122230451#Comment_122230451

Not sure I can as those climber sets need to sit flush on the two rails?

Unless I can use these: https://midsummer.ie/buy/k2fixings/2002401

But not sure if the panels would shadow themselves as they would be stuck together

SD_DRACULA

A little something like this:

Rails need to be cut to size of course they are only temp laid down but happy with the overall, zero holes inside the room below, the roof hangers are screwed into 6x2s below the roof, where the fascia will be.

The roof was leaning a few degrees north for water runoff and I tried to lift them a bit from the back to try and make it tilt south but actually ended up perfectly level so I guess 0 degrees it is

10-10-20

https://www.boards.ie/discussion/comment/122322961#Comment_122322961

Are you afraid of pooling? I'd wonder if you'll pretty quickly get residue stains on the panels as the water dries off. Suppose it's not too hard to get up there anyway with a hose.

SD_DRACULA

https://www.boards.ie/discussion/comment/122324705#Comment_122324705

Pooling on the panels themselves? Yeah I'm sure I will need to clean them up every now and again thanks to these damn birds, same on the shed panels.

10-10-20

https://www.boards.ie/discussion/comment/122324945#Comment_122324945

Yes, as most of the panels (if not all) have a rim around the sides, so you'll end up with a pool which will have to evaporate off, leaving the salts, sand and residues, etc. That tends to accumulate and harden over time causing a hardened layer on the surface. It's a pig to clean off on standard glass, but might be more impacting on solar due to some of the coatings applied. I'd recommend stepping the rails, even a degree or two.

SD_DRACULA

Hmm not sure I can, at the back it's as high as the hook permits and at the front it's as low as the roof permits.

graememk

https://www.boards.ie/discussion/comment/122325150#Comment_122325150

Aluminium bar, 2 holes, make a spacer?

SD_DRACULA

https://www.boards.ie/discussion/comment/122325229#Comment_122325229

Actually I have two options, I have some spare 250mm roof hanger bolts (used 200mm ones) could probably just replace the top 2 with these and in theory can raise them by 50mm max or do the spacer thing.

10-10-20

https://www.boards.ie/discussion/comment/122325229#Comment_122325229

Yes, that's what I'd do.

https://www.boards.ie/discussion/comment/122325246#Comment_122325246

I have a spare section of an alu-rail here (S Dub) if you need/want that.

I'd prefer to see it being done right than you having regrets later on. 👍️

SD_DRACULA

Could also tilt it a few degrees towards north like the roof is at the expense of production (which would be minimal)

...Ghost...

I would be trying to figure out a way to get the best angle south. I'm thinking of doing a frame for when I do my flat roof, or use the parapet walls as a natural height set for the panels. I'll cross that bridge when I stop bleeding money on my battery install stuff 😪