QBase low-slope mount (QuickMount)

[posplayr]

As long as no water pools around the wood footing it should last a while.

Moisture is incredibly destructive when it stays in contact with just about anything from metal (rust) to concrete (breakdown from acidity).

Stay high and dry and live long and prosper.

water doesn't last long around here including wood moisture; it need to be pressure treated.

[posplayr]

The slope of the roof must not be very great since I see no signs of shimming to level the A/C unit. They tend to be sensitive to that.

It is a low slope; The AC unit is straddling the peak. I put a level on it and they almost got it level. Maybe a 1/8" out on my 24" level.
Is that 5 mrad?

[SunEagle]

The slope of the roof must not be very great since I see no signs of shimming to level the A/C unit. They tend to be sensitive to that.

As long as no water pools around the wood footing it should last a while.

Moisture is incredibly destructive when it stays in contact with just about anything from metal (rust) to concrete (breakdown from acidity).

Stay high and dry and live long and prosper.

[solarix]

"Solar Roofing Best Practices - Low Slope Roofs presented on 5/26/2015 by Jeff Spies

http://www.quickmountpv.com/support/...e-webinar.html

They make a pretty strong case for the QuickMount system (obviously that is what they sell)"

I contend these guys are taking the solar industry down their yellow-brick-road.
In the webinar I've seen from them, they pull out nails from shingles in order to get their flashing way up under, then advise using a bit of sealer to seal the hole left by the nails! We're working on getting statements from some roofing manufacturers to refute these guys.

[inetdog]

It looks like a legitimate install using the wood. You might not have any issue with using treated wood for your solar panel array.

I know that in Florida wood is frowned upon because even treated it does not last long outside. Besides water destruction add, insects, wind, and in some cases having non fire proof material as a support structure can get you a non passing grade by the inspector.

The slope of the roof must not be very great since I see no signs of shimming to level the A/C unit. They tend to be sensitive to that.

[J.P.M.]

Hmmm. I do not remember (of course old age may be a factor) ever seeing that type of material. We have something similar to be used on the roof of an RV but not fixed structures.

That stuff looks like it was designed for high temperature flat roofs which I am guessing is common where you live now.

I have a "flat" porch on the front of my house. I've used that exact material as a coating to renew that surface. Not a recommendation, but after several years, it seems fit for purpose as a coating, but has no structural characteristics. The useful coating thickness is probably about 1/16" or so. Real bright and reflective ( Warning: wear 2 pairs sunglassses when applying, and apply in morning or in shade if possible).

Stays that way until, like every other flat, horizontal surface, it gets dusty/dirty. Best as I can tell, except for having a bit higher reflectivity (again, when new & clean), it's not much different/better/worse than other products made for same/similar purposes. Not designed for high temp. roofs as much as to reduce solar gain and keep the deck temp. down a bit maybe extend deck/roof life a bit and in the end perhaps reduce internal heat gain (although if over an insulated surface, that effect will be moderately/greatly reduced). Nice idea, but once dirty, probably not much or any better in terms of meeting the objective of keeping heat gain down by reducing solar absorbance than most any other similar but less reflective product.

[posplayr]

Hmmm. I do not remember (of course old age may be a factor) ever seeing that type of material. We have something similar to be used on the roof of an RV but not fixed structures.

That stuff looks like it was designed for high temperature flat roofs which I am guessing is common where you live now.

In the HD add they even show a guy standing on a flat roof painting it on. Yes I have used it on my RV as well and had never seen it used on anything other than that before coming here. Pitch roofs with trusses are uncommon here. I guess the heat it is cooler to not have an enclosed attic.

I have a west facing wall on a room one side of the house with plywood sheeting. That walls hits about 150 degF just from the afternoon sun. It just made me realize how much protection this 30'x45' shop (15' tall) provides as a sun shield to the rest of the house. Wishing the former owner had located the shop a little further back to shield the rest of the house, but no way to move it now.

[SunEagle]

You just paint something like this on. It is the desert and things just are not as pretentious as other locations. When I first got here (2 years ago from Ca) and saw the gawd awful HVAC units on the flat roofs it was pretty disgusting. After awhile you just accept it as the norm.

http://www.homedepot.com/p/Henry-4-7...F871/100051140

Hmmm. I do not remember (of course old age may be a factor) ever seeing that type of material. We have something similar to be used on the roof of an RV but not fixed structures.

That stuff looks like it was designed for high temperature flat roofs which I am guessing is common where you live now.

[posplayr]

I would be surprised that any basic building material/structure that could not handle a major earthquake would ever be allowed for new or refurbished construction.

Must be hard in CA to be able to put something on top of a building that will not hurt the roofing material, be blown away from high winds or shaken by earthquakes.

I am familiar with rubber or synthetic covered roofing materials. The earlier versions required some type of stone ballast to keep if from flying off. The newer materials are better but still are not totally resilient to some chemicals, oil base products or penetrations from sharp objects. I am not sure about the temperature ratings but being white must help keep your roof cooler.

You just paint something like this on. It is the desert and things just are not as pretentious as other locations. When I first got here (2 years ago from Ca) and saw the gawd awful HVAC units on the flat roofs it was pretty disgusting. After awhile you just accept it as the norm.

http://www.homedepot.com/p/Henry-4-75-Gal-287-Solar-Flex-White-Roof-Coating-HE287SF871/100051140

[SunEagle]

I don't see how anything like that would fly in California. In an earthquake the whole AC unit could fall off the 4x4's. Wood does dry out here in Az, so it would have to be treated wood and as additional precaution I would cover it with the same white coating as the rest of the roof has. This is no tile roof and requires regular maintenance (new coating every 5 years).

I would be surprised that any basic building material/structure that could not handle a major earthquake would ever be allowed for new or refurbished construction.

Must be hard in CA to be able to put something on top of a building that will not hurt the roofing material, be blown away from high winds or shaken by earthquakes.

I am familiar with rubber or synthetic covered roofing materials. The earlier versions required some type of stone ballast to keep if from flying off. The newer materials are better but still are not totally resilient to some chemicals, oil base products or penetrations from sharp objects. I am not sure about the temperature ratings but being white must help keep your roof cooler.

[posplayr]

This is relatively informative and apparently qualifies as NABCEP training

Solar Roofing Best Practices - Low Slope Roofs presented on 5/26/2015 by Jeff Spies

http://www.quickmountpv.com/support/videos/low-slope-webinar.html

They make a pretty strong case for the QuickMount system (obviously that is what they sell)

[posplayr]

It looks like a legitimate install using the wood. You might not have any issue with using treated wood for your solar panel array.

I know that in Florida wood is frowned upon because even treated it does not last long outside. Besides water destruction add, insects, wind, and in some cases having non fire proof material as a support structure can get you a non passing grade by the inspector.

I don't see how anything like that would fly in California. In an earthquake the whole AC unit could fall off the 4x4's. Wood does dry out here in Az, so it would have to be treated wood and as additional precaution I would cover it with the same white coating as the rest of the roof has. This is no tile roof and requires regular maintenance (new coating every 5 years).

[SunEagle]

Yes the "flat" roof does not mean horizontal. There is a slope to it. I have to check again, but we had new AC unit installed and the rather large AC unit was stacked on top of 4x4 treated lumber without bolting or anything else. Tucson is still part of the wind wild west ; here is a picture.
I guess they don't get many earthquakes out here. Note this was a completely professional install NOT DIY (by me)



The pictures above are of the house roof. The PV install would be on a similar shop roof install.
For me at least, water encroachment would not be as much of an issue as the roof mount is over the shop where there is no drywall and there is a concrete floor (no carpeting or wood floor). I don't want a leak as it would probably pull down the insulation attached to the underside of the roof, but the building as it stands is not perfectly watertight. The upper bricks get saturated and you can see the inside of the upper walls gets dark from dampness on the inside. We have sealed the tops of any flat surfaces, but it seems to get in anyway.

It looks like a legitimate install using the wood. You might not have any issue with using treated wood for your solar panel array.

I know that in Florida wood is frowned upon because even treated it does not last long outside. Besides water destruction add, insects, wind, and in some cases having non fire proof material as a support structure can get you a non passing grade by the inspector.

[posplayr]

Certainly any type of sealant used at the roof penetration points will reduce water leakage but may allow some to eventually pass through over a period of time due to expansion/contraction movement.

One thing to remember about "treated" wood. It will stand up to moisture that can run off it but will deteriorate if left in contact with water over a period of time.

Hopefully your "flat" roof has some type of slope for drainage and if you use wood as a footing run it in the direction of the slope so as not to create damns and let water accumulate.

I would also check with your local building code to see if "wood" footings can be used as a support structure for anything on the roof. Some localities do not allow anything that requires replacement after a few years and lumber usually falls into that category.

Yes the "flat" roof does not mean horizontal. There is a slope to it. I have to check again, but we had new AC unit installed and the rather large AC unit was stacked on top of 4x4 treated lumber without bolting or anything else. Tucson is still part of the wind wild west ; here is a picture.
I guess they don't get many earthquakes out here. Note this was a completely professional install NOT DIY (by me)



The pictures above are of the house roof. The PV install would be on a similar shop roof install.
For me at least, water encroachment would not be as much of an issue as the roof mount is over the shop where there is no drywall and there is a concrete floor (no carpeting or wood floor). I don't want a leak as it would probably pull down the insulation attached to the underside of the roof, but the building as it stands is not perfectly watertight. The upper bricks get saturated and you can see the inside of the upper walls gets dark from dampness on the inside. We have sealed the tops of any flat surfaces, but it seems to get in anyway.

[SunEagle]

I think most of those bazillion nails can't get wet unless there is a leak above them. The nails are supposed to be covered with a layer of roofing above laid after the lower levels are laid/nailed.

However, I just climbed up and looked at the flat roof on the house here and there were a bazillion exposed nails holding down the perimeter of the roofing material and all the flashing is underneath the roofing material held down by the nails. They are coated now, but not sure what was on it when installed.

On a flat roof with no shingles to slip the flashing under, I'm not sure what good the flashing really provides. It just seems like it would be easier to goop under the foot than goop under 2-4 lineal feet of flashing.

I was speaking to a friend that is an architect here in Tucson and he said on commercial jobs they tend to create an encased silicone rubber dam/block around a penetration.

My DIY idea, was that rather than put a mounting foot like the QBase mount directly down on the roof paper/material and risk potentially cutting it with any loads/moments on the foot, I would drill a shallow hole with a hole saw on the back side of some treated lumber, fill the underside hole with sealant and put down a lag bolt or screw through foot, and through treated stick of lumber and through the pocket of sealant when laging/screwing to the roof truss. The roofing material is now sandwiched between wood and not metal and the screw is encased in a pocket of sealant covering the penetration.

While I did not get the idea from it, I saw something similar where the aluminum foot has a countersink on the bottom of the foot and a screw is put through a rubber seal that compresses between the top of the roof and the countersunk aluminum foot. I think I would trust a 30 year chalk rather than a rubber compression seal even if I had the special foot.

Certainly any type of sealant used at the roof penetration points will reduce water leakage but may allow some to eventually pass through over a period of time due to expansion/contraction movement.

One thing to remember about "treated" wood. It will stand up to moisture that can run off it but will deteriorate if left in contact with water over a period of time.

Hopefully your "flat" roof has some type of slope for drainage and if you use wood as a footing run it in the direction of the slope so as not to create damns and let water accumulate.

I would also check with your local building code to see if "wood" footings can be used as a support structure for anything on the roof. Some localities do not allow anything that requires replacement after a few years and lumber usually falls into that category.