Installation on a lightweight tile roof

[twitter]

Hi Folks,

I'm in SF bay area and in the process of getting quotes for solar installation. I've a 15 year old lightweight tile roof in very good condition. I contacted 6 local companies with good reviews on yelp and two of them are not interested because of lightweight tiles. They were worried about cost of replacing damaged tiles during installation. Others were okay but I guess they may included the cost of tile replacement in their quotes. I got quotes between $3.75 to $4.75 per watt for about 4kw installation with LG panels + enphase inverters.

How is the other folks experience with installation on a lightweight roof. Does it require a different mount or just the proper roof walking technique. What questions should I ask the potential installers?

Also, what would be decent cost per watt for a mid-grade panel and inverter ( LG/Solarworld panels and solaredge/enphase inverters). Roof is south-east facing and there is same shading in the afternoon from the tall redwood trees on the west side.

Thanks

[J.P.M.]

FWIW, I've got lightweight tiles on my roof. I live in an HOA with only concrete (most of it lightweight) or clay tile. The prices around my HOA are, on average, probably higher than elsewhere, but most of that is, IMO, due to customer ignorance as well as advanced age that somehow enables old folks to get screwed more quickly and more easily, rather than roof material.

A few and an increasing # of vendors try to sell the idea of removing the tiles from under an array. For a lot of sound reasons, that is not allowed by the CC & R's in my HOA. Vendors bitch and then comply. The price does not go up.

[Stopsignhank1]

I don't know if I have lightweight tiles, I think I do. I know I tried once to go on my roof. First step I cracked a tile and have not been up since. When I had my solar put in they broke a lot of tiles. They did not charge me for the replacement of any but I know it was a bitch for them to find them. They had to go look around to 5 or 6 different suppliers to find them. I know the company and they are professional installers so it was not Joe's electric and pool repair who did it.

[J.P.M.]

I don't know if I have lightweight tiles, I think I do. I know I tried once to go on my roof. First step I cracked a tile and have not been up since. When I had my solar put in they broke a lot of tiles. They did not charge me for the replacement of any but I know it was a bitch for them to find them. They had to go look around to 5 or 6 different suppliers to find them. I know the company and they are professional installers so it was not Joe's electric and pool repair who did it.

Walking/working on tile takes more time/care and some thought. Walking on the lower edges away from the corners helps. Removing/replacing tiles is often one way. Plywood etc. is another way with required care taken for anchorage to deal with windage, roof slope, etc. It can be done, but takes time and some effort. I see it all the time. Some breakage is probably inevitable. One partial fix to deal with mismatch for replacement tiles is to put the new ones under the array and play musical chairs with the broken ones and those removed from under the array.

[twitter]

Thanks JPM and Stopsighhank1. Appreciate your helpful responses.

[ncs55]

Tiles always break even if you walk correctly on the overlap. If there is a small chunk of tile or grit between the overlap area and you step on it the tile will at very least crack. Never step in the center as there is nothing but air under that part. I am not sure what you consider lightweight tile. If it is like the monier tile that has a look like a shake roof then yes be careful they break easily. Any terra cotta type or cap and pan style will have to be removed for walkways and then reinstalled. IMO, it is not a good idea to put a torch down or comp under the modules and then stack tile around the array and for a lot of reasons. Can you take a picture of your tiles, maybe from a ladder or without actually going on to the roof? Usually the manufacturer has a logo or name on the underside, this is helpful for finding replacements. A good installer will account for a certain amount of tiles getting broken during the install and add that to the bid. A lot of our customers have stacks of tile and are willing to supply them for us. Others we have to search for and can usually find at the tile bone yards if they are not being made anymore. Using plywood is risky and hard to secure without slippage. IMO, if you cannot walk on most tiles without breakage, then stay off of the roof until you have been trained in proper techniques.

[BenL]

I'll give you my advice after I give you my background.

I use to work for Vivint Solar and managed an office based in San Leandro. I no longer work for Vivint as I am with a company that offers all sorts of solar options. I have personally sold light weight tile jobs which are a fairly common roof in areas like Castro Valley. In my experience it is very risky and Vivint Solar will no longer install on that roof type. The best would be to weigh one of your tiles. The job I am referring to was a lightweight 6.9 lb flat concrete Tile which is no longer manufactured. I personally saw the install take place and the aftermath of it. The mount that is used on the heavier tile fit the lightweight no problem. However, tiles were broken and lots of them. We picked up hundreds of replacement tiles at vintage tile in San Jose. Sort of a graveyard for unused non manufactured tile. Even with replacing the tile during and after installation the roof still leaked and the customer is gettin a reroof at Vivint solar expense Witt a heavier duty tile. I think you will find companies that can do the roof, but honestly it is a nightmare. My recommendation would be to get a solar company to get you a quote to replace the areas under the panels with comp shingle. This is a fairly common practice and you can get a decent deal on it. I have some contacts if you are interested who can give you a good offer. I'm able to get installation of LG panes and emphases like you mentioned for 3.50 a watt before tax credit or 2.45 when applied with the tax credit.

[ncs55]

Are you referring to those tiles that look like they are concrete and fiberglass? First of all I spend most of my time on roofs and I have been taught by roofers. If that roof was leaking it is not the fault of the tiles. More likely the underlayment was in need of replacement and the installation crew did not seal or flash the penetrations correctly. I see this as a common practice of some installers that just want to make a non complicated sale and the salesperson who never gets on the roof will not see as he closes the sale based on numbers and in the first visit. Just so you know, water gets past tiles all of the time, ask a competent roofer. What stops the water is the underlayment. And the problem with putting comp under the modules is that to do it properly, the whole section of roof needs to be done, not just the one section under the modules. And if the standoffs were double flashed properly even if the tile leaked water would not make it to the penetration and would have to weep through cracks or tears in the underlayment. Someone at that company did not do their job and the company had to pay the price. Also it is not appropriate to solicit your contacts in the manner that you are using this forum for.

[J.P.M.]

I'll give you my advice after I give you my background.

I use to work for Vivint Solar and managed an office based in San Leandro. I no longer work for Vivint as I am with a company that offers all sorts of solar options. I have personally sold light weight tile jobs which are a fairly common roof in areas like Castro Valley. In my experience it is very risky and Vivint Solar will no longer install on that roof type. The best would be to weigh one of your tiles. The job I am referring to was a lightweight 6.9 lb flat concrete Tile which is no longer manufactured. I personally saw the install take place and the aftermath of it. The mount that is used on the heavier tile fit the lightweight no problem. However, tiles were broken and lots of them. We picked up hundreds of replacement tiles at vintage tile in San Jose. Sort of a graveyard for unused non manufactured tile. Even with replacing the tile during and after installation the roof still leaked and the customer is gettin a reroof at Vivint solar expense Witt a heavier duty tile. I think you will find companies that can do the roof, but honestly it is a nightmare. My recommendation would be to get a solar company to get you a quote to replace the areas under the panels with comp shingle. This is a fairly common practice and you can get a decent deal on it. I have some contacts if you are interested who can give you a good offer. I'm able to get installation of LG panes and emphases like you mentioned for 3.50 a watt before tax credit or 2.45 when applied with the tax credit.

Replacing the tiles under an array with comp. shingles is a way to build in problems where none may have existed. It will do no more than make life easier and more profitable for the vendor, and leave planted problems for the homeowner with nothing to show in the way of benefits. It's a B.S. method, that's been about beat to death on this forum in the past. Folks who know what they are doing and are pros, know how to work on and with rigid and breakable roofing materials. Some breakage is a fact of life, but as ncs55 writes, it's not a good idea to put comp under an array.

Everything in my HOA is tile, either concrete (and a lot of it lightweight) or mission tile. There is not one array, of 95 or so, that has comp. shingles under it. I noticed that vendors started pulling that B.S in earnest about 5-6 yrs. ago around here, probably as a cost saving measure, and was/is usually proposed by lower quality vendors. SolarCity and Vivant being the two most persistent in their attempts. The A.R.C. guidelines were changed to prevent such crap from happening. It may be a fairly common practice, but it's not a good one.

BTW, while Vivant has bitched/moaned about not being allowed to use comp. under an array, they have not done it, and have installed over concrete tile.

[twitter]

Yeah, the tiles look like the Monier shake lookalike. I weighted one and it was 7.4lb.

[ncs55]

I have a job that is a remodel that we have not started yet, (still in permitting), and those monier shake look alike's are what we are dealing with. The light tiles are sturdy, but at the overlap they do not rest on an even surface like a flat tile or even an s tile, therefore even walking carefully they can and still break. I have already placed an order for around 60 of them to have while installing. There should be a nice pile left over for the homeowner when we are done. They are difficult to work with though, sometimes they break when cutting for the flashings and then sometimes break after the cut while trying to put them in place. Even with these problems it is still less expensive to deal with the mentioned issues and keep it all tiles as opposed to having a comp installed under the array, which this customer specifically does not want anyway. Another thing to consider is that comp will catch on fire easier than underlayment that is beneath a layer of concrete. More importantly, consider that the light tiles and the weight on the roof directly relates to the load bearing weight of the rafters or trusses. Have your installer make sure that your roof can support the additional weight of the modules and racking. That is another issue for us to deal with as we are in earthquake and fire country. Engineered roofs sometimes need additional engineering and supports added before the external weight is applied.