Home Improvement

Home improvement questions? Ask a handyman for answers

Ask an Expert,
Get an Answer ASAP!

This answer was rated:

I have a 5000sqft warehouse with a flat roof. It snowed a…

I have a 5000sqft warehouse...
I have a 5000sqft warehouse with a flat roof. It snowed a few days ago and once the snow melted on the roof I have a few leaks and some spots have about 1 cup of water fall on the floor. Than the next day the weather was good no rain or snow but I got more water on the ground. Once I went on the roof and saw no water on the roof but water was still leaking into the building and the ceiling tiles were getting wet. What is the best way to find where the leaks are coming from on a flat roof? Also, what does it mean that days later the water is still leaking inside the building?
Show More
Show Less
Ask Your Own Home Improvement Question
Answered in 5 hours by:
3/16/2018
Thomas
Thomas, General Contractor
Category: Home Improvement
Satisfied Customers: 40
Experience: Owner/ Vice President
Verified

Hi and thank you for choosing JA! This is one of the most frustrating issues with a flat roof! We have done two of them in the past 4 months, one about 20,000 SF over a retail plaza and one about the same size as yours, 5000 SF over a retail/ residential building. The larger roof was about 12 years old and the smaller one about 10 years old. Over time, the harsh 4 seasons had taken its toll and we were able to see some cracking in the surface (not necessarily open cracks) and some open cracks (size of a quarter) around the vent and drain pipes coming up through the roof. A couple things, a ceiling leak on the inside IS NOT necessarily an indication of where the failure or roof is leaking on the surface. Many times the leak, or water, once below the surface can find a joist or meal substrate, and run along that until it falls to the ceiling below and ultimately leaks into the space down to the floor. Also, when this is the case, the water may collect under the roof and drip for days until it dries up...even though the rain has stopped or the snow has all melted and dried on the roof. It is very difficult to pin point the leak location after the roof has dried. If there is "ponding" of water on the roof and the leak is near that area, that might be an indication of where to start the investigation. I do not recommend trial and error patching. This can be time consuming and frustrating. I recommend starting with an experienced roofer who has a trained eye for locating "possible" leak locations. Most experienced and reputable roofers can and will use moisture meters and/ or infrared equipment to see where the moisture is located below the surface of the roof...this is really the only way to accurately find where the roof leak is starting from and where the water is running below the surface. Keep in mind that both moisture meters and infra red imaging (the latter relies on temperature differences presuming wet areas are cooler) cannot accurately pinpoint a leak source if no water is present, that is if too much time has elapsed since the last rain or last leak. Again, when a flat roof has a leak, it is common for the leak to still be present on the inside after the rain has stopped or snow has melted. The best solution, avoiding a trial and error patch method, is to have a trained roofer come out and do a thorough inspection, and, if too much time has past, they will do a water test (flood the roof) and conduct a visual and meter test at that point. If the roof has past its useful life, a complete tear off and replacement is always the best solution, thus providing another many years of warranty for a sound roof. If the roof is still relatively within its useful life, then a repair can be the most cost effective solution, even though it might take a couple tests and patches to completely solve the problem. When a flat roof is in the 15 - 20 year old range, it is time to consider a new roof...but, that said, a trained roofer and an inspection with a roofing report, is the best place to start. I will say this...a reputable professional roofer, should give you a report noting the potential problem areas, with costs associated for the repairs and a recommendation for complete replacement if they feel it is necessary with a cost for that as well...THE REPORT SHOULD HAVE BOTH ALTERNATIVES LISTED! For a commercial structure, this should be common practice and I suggest having more than one roofer look at it. We do this as common practice and most of my respected competitors do this as well...as part of the proposal and should not cost you anything for that level of proposal. I hope this has been helpful! I know these types of leaks are FRUSTRATING!!! But with a good, professional roofer, they can help you solve your problem as painlessly as possible! Thank you for choosing JA!

Thomas
Thomas, General Contractor
Category: Home Improvement
Satisfied Customers: 40
Experience: Owner/ Vice President
Verified
Thomas and 87 other Home Improvement Specialists are ready to help you
Ask your own question now
Customer reply replied 5 months ago
Thomas thank you for your response. Are you referring to a thermal camera?Also, how does the moisture meter work? Is the probe that you use?

Thank you for the rating...greatly appreciate it! There are a number of different "meters" that roofers can use. You are correct about the infrared meter...it is a thermal imaging camera. This is particularly good at identifying areas, specifically where insulation is under the roof surface, and can identify wet insulation or areas that hold the moisture for long periods of time before drying out....but yes...a thermal imaging camera. I usually start with this since I can identify entire areas in the most efficient time frame particularly on larger roofs. We also use a moisture meter, in our case, it looks like...hard to describe...those old style push lawnmowers, where we run the unit over the roof that has a sensor across the bottom with a meter that records the moisture attached to the handle and it will record obviously wet areas and dry areas as we go, specifically if we have an idea where the problem is at. They do sell these at home improvement stores, more hand held versions at a relatively inexpensive price, however the one we use is considerably more expensive and gives us the most accurate readings we can expect. I will say this, with all the technology, we do not always find it the first time, but we do provide a level of service depending on the extent of the roof...in other words, we are very transparent in our assessment to the customer since we know, leaking roofs, depending on their age, is not an exact science. A cut as small as a penny in a 20,000 SF roof can create a continuous problem without finding it. That is why using the technology that a reputable roofer should have, is always the best way to give you the best chance to solve the problem. In any case, using thermal imaging and the moisture meter readings, we do a pretty good job of getting it right the first time. Again, full transparency, some roofs are old and in such bad shape, but the owner doesn't want to or have the money to do a complete tear off and we do our best to mitigate the issue as best we can...but we are very up front with our assessment and typically will not warrant this type of repair. If your roof is not that old and has life left in it, a good roofer will tell this and provide a level of warranty relative to the age of the roof...this is what you should look for in their proposal as well in addition to the detailed assessment. Another thing we provide, if we cannot warrant the roof due to its age, is we will include either one or two return trips, in lieu of a warranty, to make sure the customer knows we are concerned with satisfying them as best we can given the condition. Thank you again for the positive response and I hope this has been helpful as well! Thank you very much for using JA!

Ask Your Own Home Improvement Question
Customer reply replied 5 months ago
Understood. I will look into getting a thermal imager. Now I have an excuse to get one and can be used for so many other things. Once I acquire the imager I would essentially use it inside the building and I'm assuming that blue will indicate where the water is sitting and a line would indicate where the source is?I was also thinking about using some kind of colored die in different parts of the roof and based on the color would have some sort of idea where the origin of the leak would be. Have you ever done that?Any other tips?

Depending on the type of "imager" you are using, i.e. gray scale or color. For us, we use a color imager and red is hot, blue is cool. During a hot, sunny day when the roof is extremely hot, the imager will show us "blue" areas, where water or moisture is located and is typically cooler than the roof surface. Depending on the conditions, when the roof cools, moisture, or water, tends to hold the heat longer and will show up as red, indicating a wet area. When we take an image, we are able to differentiate the hot and cold areas enabling us to identify potential problem spots. We then spray paint around those areas and do a visual inspection of those areas. To your point about a dye test, we don't use that method since we can't really get in between the substrates of the roof to visually see the the water and how it runs, but we have identified an area and have done a controlled "flood" test. We will look at the readings from the thermal imager or the moisture meter, and actually hose the area down, if we cannot find visually a spot that may be the cause, and see if we are getting a leak in that location. If we do not get any leak in an area that moisture is built up in, that tells us the leak is not in the location that the water is gathering underneath the surface, but it is running to that location. we can then move our "flood" technique to see how the flat roof is pitched and where the water would be running from. It is possible to see a "line" as you stated or " stream" from the imager and even the moisture meter. If you are going to try and locate and fix the area yourself, start with the thermal imager, and then a flood test if you cannot pin point the source from the image. The image SHOULD give you a good idea where the leak is at. Your roof is not that large relatively speaking...I keep thinking in my mind about this 20000 SF roof we did and it was a challenge given its age...and the leak was over the produce department!!! Also, start investigating around your vent stacks and any other ducts, roof curbs or chimney stacks. This is typically where we see the sealant around those breaking down before any roof degradation. This was the case on the 5000 SF roof we did. It was old and really needed replaced, but we found the sealant around the stacks had failed and the parapet wall flashing was not properly sealed any more. We probably saved the owner thousands taking care of that and he will be able to get more years out of his roof. The issue with leaks around stacks is that they will run with the piping or ductwork and then fall "somewhere" along the piping route. This particular leak was coming in the third floor about 20 feet away from the stack!

Ask Your Own Home Improvement Question
Customer reply replied 5 months ago
What are you thoughts on the rubberised roof paint?

The coatings are an acceptable, short to medium term, cost effective option. Rubber does offer good elasticity and is most cost effective. More recently, we have done a couple aluminum coated over asphalt roofs. The aluminum coating helps reflect the ultraviolet rays, doesn't break down as fast as the rubber and provides a more energy efficient coating, i.e. reflects the heat from the sun as opposed to absorbing it. It is more costly from a product standpoint than rubber. As a matter of fact, the repairs we did on both the 20000 SF roof (a complete coating over the entire roof) and the repair on the 5000 SF roof (sealing around the stacks, etc. and a 6' x 45' coating over the back) was an aluminum paint on coating.

Ask Your Own Home Improvement Question
Customer reply replied 5 months ago
I started my hunt for the leaks and I found alot of cracks that were wet and its been 3 days since it rained or snowed so I applied the rubber cement. No water on the roof at all. I'm assuming that since we had a brutal winter the cold weather
cracked the rubber cement. Am I correct?Also, what is the best way to apply the rubber cement? I used a trowel but applied a little to much on the ends and as a result wasting probably about 25%.Do you recommend applying the rubber cement every year since the winters here in NY are brutal?So once the rubber cement is applied between the seams I can then applied the aluminum paint?

OK! Your pics are great! Applying too much is ok other than the waste issue, but troweling on KARNAK is just fine. KARNAK is also a good low temp patch since you are in NY, which is good to know as well. If you do not coat the roof, then it would be a good idea to check your roof after each winter for new cracks, but your patches should be ok for a few years. The KARNAK product, like most good products has good elasticity. Given you are seeing some cracking, you will want to check for the formation of other potential spots, but your recently patched spots should be ok. If you coat the roof with an aluminum paint, make sure your recent patches are dried and cured. This time frame will vary depending on temperature. But...do not coat the roof until the temp is consistently above 40 degrees at a minimum for at least a couple weeks. The surface should be cleaned (remove large debris like rocks or stones by hand, then blow the dust and dirt off the roof). Make sure if you are applying an aluminum coating, you do it when you have a couple days of no rain in the forecast. Check your product guide, but usually it takes at least 24 hours to dry depending on temp, higher temps take longer. Again, since you are in NY, the aluminum application should be done when you have a consistent temp over 40...we are in Ohio so we have a similar weather condition. Yes...the brutal winters do play havoc especially on the older roofs, but recent repairs should be ok since most products are good to the lowest temps we see, so your patches should be ok for a few years if not longer. From your pics, your roof surface looks pretty good! It looks like the seams are your main issue. An aluminum coating will help preserve the roof and should give it many more years and should help any seam issues as well as help with reflecting the summer heat as well. A good elastic patch over the seams should really help your problem and the product you have, KARNAK, is a good one.

Ask Your Own Home Improvement Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a home improvement expertLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Thomas Your Own Question
Thomas
Thomas
Thomas, General Contractor
Category: Home Improvement
Satisfied Customers: 40
40 Satisfied Customers
Experience: Owner/ Vice President

Thomas is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Thank you for the expeditious answer. It's good to know you're out there and awake in the wee hours when I finally have time to ask questions about my Jenn Air.

JeanRiverhead, NY

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

< Previous | Next >

Meet the Experts:

Brian

Brian

Architect

2,153 satisfied customers

Licensed Architect- 17 years, L.E.E.D. AP

The Home Smithy

The Home Smithy

Home Builder

2,084 satisfied customers

#1 Home Improvement Expert 30+ years experience

Steve G.

Steve G.

Handyman

221 satisfied customers

VP of electronic repair company and home theater advisor.

StructuralEng

StructuralEng

Civil Engineer

14 satisfied customers

Licensed Structural Engineer

Eric M. Bright

Eric M. Bright

We Don't Comprehend the Word Can't!

1,734 satisfied customers

I've been been doing things for my clients that others have said cant be done for over a 1/4 Century

Phil

Phil

Mechanical Engineer

711 satisfied customers

Retired contractor, 51 years experience

Martin

Martin

Electrical Engineer

689 satisfied customers

Design, construct, fix and grow stuff around and in the home.

< Previous | Next >

Related Home Improvement Questions
Garage attachedto the house..waterleks frommiddle of ceiling
Garage attachedto the house..waterleks frommiddle of ceiling only when rainy windy storm then stops.no water in house? … read more
Machinc
Machinc
Retired
1,022 satisfied customers
We r having very hard rains, carpet is wet (2 feet away from
We r having very hard rains, carpet is wet (2 feet away from wall and sliding door, also same wet spot is 3 feet away from fireplace. Have had door checked twice (no problem found) walls , door and fi… read more
WCohn
WCohn
Journeyman Plumber
Journeyman License
1,751 satisfied customers
I just tarred my roof a few weeks ago. It snowed and after
I just tarred my roof a few weeks ago. It snowed and after the snow melted the tar is now yellow in color and soft to the touch. What does this mean?… read more
Machinc
Machinc
Retired
1,022 satisfied customers
I keep getting water in my house, mostly during winter when
I keep getting water in my house, mostly during winter when snow melts. But today noticed a new stain. I comes in through bottom of second floor window....the wallpaper gets wet...then goes across dow… read more
Dovetail Greene
Dovetail Greene
President
434 satisfied customers
35 yro town house, 3 bedroom.. row type where several joined
35 yro town house, 3 bedroom.. row type where several joined together. two stories with basement. problem is in top level (2nd floor) their seems to be very small leak from the roofing shingles, indic… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
Hello. My 1929 house has a roof leak. I have a flat roof
Hello. My 1929 house has a roof leak. I have a flat roof (3 degrees slope) that meets a peaked Spanish tile roofed front portion of my house. The leak occurs under heavy rain and wind. I can see a cle… read more
Brian
Brian
Architect
Bachelor's Degree
2,153 satisfied customers
I have a building that has a flatroof. It was not leaking
I have a building that has a flatroof. It was not leaking this year. Yet with this last super cold weather/snow/ice and then it all of a sudden got warm super quick and lots of rain and melting. The r… read more
canuck the pro
canuck the pro
281 satisfied customers
Recently my roof has been creaking, making noise, and we returned
Recently my roof has been creaking, making noise, and we returned home to find the mirror black splash in the kitchen cracked. A combo roof flat Redone 2 years ago and pitched with tile, a seam leak r… read more
dsg_architect
dsg_architect
26 satisfied customers
hi there, we are having problems with the ceiling in our house.
hi there, we are having problems with the ceiling in our house. the house was built in the 60's, it is considered a flat roof, it has only a little slant. when we bought the house 7 years ago all was … read more
Jerry
Jerry
Plumber
High School or GED
1,456 satisfied customers
i roofed a home under contract -finised up with the flat roof
i roofed a home under contract -finised up with the flat roof over the porch-when it rained that nite-the roll roofing didnt hold up as it has in the past 20 yrs and my client had a leak in there kitc… read more
JimJML HOME IMP
JimJML HOME IMP
High School or GED
27 satisfied customers
I have a vaulted wooden ceiling on a second floor bedroom with
I have a vaulted wooden ceiling on a second floor bedroom with a huge wooden beam at the peak. This main support beam does not extend thru the walls to outside. Today on each end of the beam, heavy co… read more
Rich
Rich
Retired Master Electrician
Vocational, Technical or Trade Scho
652 satisfied customers
Probably a long shot, but here it goes. I received a call
Probably a long shot, but here it goes. I received a call from our friend who told us that she is experiencing flooding in her house. When I got there I found that the flat roof was indeed leaking, bu… read more
The Home Smithy
The Home Smithy
Home Builder
Vocational, Technical or Trade School
2,084 satisfied customers
I have a tri-level home,a leak started in a room right below
I have a tri-level home,a leak started in a room right below where the upper level is please help me.… read more
Stephen Cutler
Stephen Cutler
Registered Residential Contractor
licensed residential contractor
1,851 satisfied customers
thick snow in north-east england & water dripping from top
thick snow in north-east england & water dripping from top of bathroom window inside. Can this be guttering. I,m a widow & don,t know what to do. I live in house & bathroom upstairs but conservatory u… read more
Stephen Cutler
Stephen Cutler
Registered Residential Contractor
licensed residential contractor
1,851 satisfied customers
I discovered a water leak around a light fixture in our master
I discovered a water leak around a light fixture in our master closet after a heavy rain. The bedroom and a bathroom adjoining have cathederal ceilings and trying to reach the spot from the attic is i… read more
Rick the plumber
Rick the plumber
Owner
9,857 satisfied customers
I purchased a 31 year old home and two days after I moved in
I purchased a 31 year old home and two days after I moved in we had water leaking through the drywall and into our family room. We have a wood burning fireplace and chimney that is at the base of the … read more
Charles
Charles
Owner
FCC Communication License
738 satisfied customers
I live in a 2 story townhome. Vinyl siding. 13 yrs old. Well
I live in a 2 story townhome. Vinyl siding. 13 yrs old. Well maintained. We recently had 14" of snow and VERY cold temps here. Today it warmed up to 28 & there was a LITTLE melting around windows, in … read more
tinman
tinman
n/a
Vocational, Technical or Trade Scho
171 satisfied customers
I have a duplex which has no insulation in the 18 inch ...
I have a duplex which has no insulation in the 18 inch space between the ceiling and the roof. Building size is 26'X40' Should there be insulation in there? Without insulation the heat loss is melting… read more
Terry
Terry
Vocational, Technical or Trade Scho
48 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x