Roof Leaks caused by HVAC roof mounted systems. Air Conditioners on roofs that leak can cause hundreds of dollars in repairs. The problem is finding the responsible party. I can’t tell you how many times, year in and year out, how I have been blamed for a leaky roof I installed, only to find out that someone installed a AC on the roof poorly years after I did the roof. When it leaks, who do you call, the roofer! The photo to the left shows how a HVAC contractor from the Sacramento area has bent , broken and stuffed his roof mount HVAC stand poorly into this roof. There is no way this roof would not leak, and it did, and who did the home owner call? Yep, you got it , me. The shingles and underlayment needed to be repaired and during this job a broken rafter was discovered and replaced.  As you can see to the right the unit’s stand on the bottom left is extended more than the right side to make up the sag in the roof. The HVAC contractor cut a rafter and it loaded too much weight on what is called the cripple rafter which had no purlin support.

{ A cripple is a rafter that runs from a hip to a valley} This HVAC contractor that did this horrible job is a large company that does a lot of advertisement, but will never get a referral from me because of this type of work. There were many issues with this installation and don’t get me wrong because for the most part HVAC contractors are great. This installation was very poor and did not get inspected by the Building Department. window ac units with remote controlI have seen many maintenance issues on a Air  Conditioners that also caused leaks. window ac unit not coldI hate having to tell the customer they need to call the HVAC Contractor that work on the roof recently to come back out and fix this problem. how to secure window ac unit from theft

Did you know I have seen small 1/2 holes stabbed into the elbow so the HVAC contractor can temp/test the return air, then leave that little hole. I could go on and on but I think the point is made. This area of the roof is most important to get right and hiring the best to do the two jobs is critical. I have for years developed great working relationships with HVAC Contractors. As a roofing contractor it is good to have a few you can trust and use because things can really go well if the two know each other and work good together. The reason why is this, when the roof and HVAC are being done at the same time, both contractor that have worked together  both understand each others job responsibilities. Of course having both jobs done by the same contractor would have the best results. There are not to many contractors that cross over trades, so having the two contractors having past experience together is a good scenario. It normally goes like this. The old HVAC removed.

The roof is removed. Exposing the roof can be useful to the HVAC contractor setting the new curb or stand. Having the heavy AC unit off the roof the roofer can install the roofing easier and making a clean good looking job. The HVAC contractor then lifts the new AC and sets it on the stand and seals the unit to the plenum. Best of both worlds, if both are done at the same time. If not I advise an inspection of the both contractors to make sure this area of the roof perform well for years. Water Dripping From RV Roof AC Question: We recently purchased an older 5th Wheel. When the AC was turned one the first time, the AC works fine, but water was dripping down the outside of the camper. Any suggestions to solve this problem would be greatly appreciated. We are an older couple and are anxious to get moving with this unit. Robbie: Water running down the side of your unit from the AC is a good thing. Just like water dripping out from under your car when you use the dash AC. There is a hole in the AC allowing the water to run onto your roof and you seeing this water tells you the AC is working fine.

When a customer calls me saying they are having a problem with there AC cooling, one of the first questions I ask is "Do you have water running down the side of the coach". Relax and enjoy, everything is fine,RobbieThis article is from an archived issue and may contain out-of-date information. Please refer to the main Your Business page for more current articles. Branch Circuits--Required Receptacle Outlets, Part XII April 2003 © 2003 - 2016. All Rights Reserved.Electrical Contractor: 3 Bethesda Metro Center, Suite 1100, Bethesda, MD. Burbank leader - Photos Photo Gallery: Air-conditioning units air-lifted to new Burbank Ikea store roofThe Bow Tie Royale 6 Cinema Theater contracted Commercial Roof USA to install an air conditioning unit on an EPDM flat roof at 542 Westport Ave., Norwalk, CT. The curb was supplied by the The Heating and Cooling Company located in Norwalk, CT.  Mike Tavolacci marked exactly where the curb would be positioned on the roof.

We installed the air conditioner curb with vibration dampers used to minimize noise. Video Transcript - Air Conditioner Curb Installation on a Flat RoofHi I’m Erik from Commercial Roof USA And today they called us to do this commercial roof It’s an EPDM roof and they called us because they need us to flash a 10 ton A/C unit Now this needs more than just flashing done.This roof is unleveled so were gonna have to level it you can see there the bubble is off a little bit So um what we are gonna do is we’re gonna level it first. Then on the inside there where you can see the orange marker uh we’re gonna cut the vent the vent or the intake vent and then we’re gonna have to flash the whole thing and uh the way we do it is a is a double step process where we flash on the inside and on the outside so they’ll never have a leak again. I’ll be showing you every step of the way.This is how to flash a 10 ton A/C unit Alright well we’ve installed the ah curb and we vulcanized the unit here and uh we’ve installed this tarp on here so that when the HVAC people are ready they can just put the unit down on top This is how you install and vulcanize a curbThe a/c curb installation process required us to cut through the EPDM rubber at the markings.

Then, we removed a 3″ insulation isoboard. Under the the insulation was a 5/8″ gypsum board. After removing the EPDM rubber, insulation, and gypsum board, we had to cut through the metal sub roof, which is the opening for the intake duct to the A/C unit.After the opening was made for the duct work, we placed the curb into position. Because the roof is slightly slanted, one side of the curb had to be lifted to be level. After leveling the curb, we anchored it down with 4″ screws to the metal sub roof.After anchoring the curb, we vulcanized the entire curb with EPDM cover tape, and carefully added the flashing, as well, to tie it into the existing rubber roof.We Provide the Following ServicesResidential and Commercial Flat RoofsInstallation of 2 Ply Rubber roofingRepair of all flat roofsReplacing of skylightsRepairing metal roofs inexpensivelyProvide Free Estimates and Advice and best solutionsRe-positioning Drains to cause positive flowInstalling Scuppers to remove pooling waterA/C curb installationFinding and Repairing all leaksRoof Drain

Use this email to send images of your roof problem. Text Messaging:  203 858 0080 Images of A/C Curb Installation Steps:Make sure all the measurements are correct and the location is properly marked.Prep surface area by removing all debris and water. 3.  Cut the rubber and insulation away to expose the metal sub roof. 4. Below is the metal sub roof after the EPDM and insulation was removed. Use a metal reciprocating saw to cut this section out.Extreme caution must be taken during steps 3 and 4 because there could be electrical wires on the underside of the metal roof. In this case a drop ceiling hanger wire was attached to the the metal so we were fortunate enough to remove it without disturbing the drop ceiling.5. Placing curb into position and ensuring it is level:Since the roof was slightly slanted, we had to lift the curb by 5/8″ on one side to get it level. It is important to have it absolutely level; if it is not level, the bearings will wear of faster on the A/C unit.6.

The roof is slightly slanted and it was necessary to level the curb before we started to install the flashing.  We used 5/8″ wood strips under the one end of the curb. After getting it level we secured the curb to the roof with 4″ screws that held is into place.7. Vulcanizing and flashing the air conditioner curb.Once the curb was leveled we covered the entire outside of the curb with EPDM cover tape. To flash the curb, it is necessary to clean the existing roofing surface very well. We used lacquer thinners and rags to remove all the oxidation from the surface where we needed to adhere the new EPDM cover tape.After the cleaning, we brushed primer to the surface and waited for it to dry. After a touch dry test, we installed the cover tape and flashed the entire unit.8. In the case of an EPDM roof, it is necessary to use compatible material to do the flashing. In this case we used EPDM cover tape. It is very important to use a roller to roll the cover tape so it can properly adhere to the EPDM rubber.9.

Cover the curb with a tarp.It is difficult to coordinate two different trade crews to complete a A/C unit installment on the same day, but if the A/C contractor marks out where the curb will be installed and leaves the curb on the roof, we can then notify them when the curbing has been completely installed and is ready for the A/C installation.10. The proper material for the right jobWhenever there is curb to be installed or flashing that needs to be done, it is important to use compatible materials. On an EPDM roof, only EPDM materials must be used. The same principle applies to a Modified Bitumen Torch Down roof; only Modified Bitumen materials should be used. Sometimes, we find that this principle is not practiced by other roofing contractors. In the images below we are flashing a curb with Modified Bitumen Membrane Torch Down material.The image below is also a Modified Bitumen Membrane curb installation. It is essential that a special tar be used to try and seal any flashing, but it should be used very sparingly.