Asked on Jan 03, 2016

Back porch with a flat roof and sky lights leaks

by DJ
We have a screened in back porch with a flat roof that leaks. We have tried caulking it and that lasted until we had 5 days of heavy rain. We would like to replace it and maybe tie it into the main roof we but don't know how expensive that would be or, if maybe there are other options. Any ideas?
  18 answers
  • Jen Jen on Jan 03, 2016
    Just found severe mold in our bathroom skylight..not good! Tearing what we can out and losing the skylight....Going to re-drywall the ceiling and just get rid of it!
  • Jan Loehr Jan Loehr on Jan 03, 2016
    We have a builder built screen porch with two skylites ...enjoyed trouble free for 20 years, no leak problems at all...the roof is finished with the same tiles as the roof of our I would suggest a few contractors professional opinions as to how to fix your problem so you never have to deal with it again...I would not make this a do it yourself fix.
    • See 1 previous
    • Rita Botha Rita Botha on Jan 04, 2016
      @DJ I have fought a similar problem now for almost five years, with two slanted roofs (house on one side and garage on the other) and the area in between covered over with a flat roof (only 15 degree fall into the valley gutter). The valley gutter is a wide, high gutter feeding water out to two sides to accommodate the run-off from both slanted roofs. However, all the "patching" solutions we could find have been tried, including roofing tar which was applied with heat to the entire flat roof area. A tree which was positioned in such a way that it was causing debris into the gutter, was trimmed back and every few weeks I climb up to check that the gutter has not been blocked. Sadly, none of the above measures have been successful for longer than a few months. I've just had the best run of "dry", and that was after the roofing tar - and it held only for 8 months. Two things I would like to leave with you to think about: 1. The previous owner of my house put this roof on as an "afterthought" and it was a DIY job. I would not recommend this to anybody who is not a qualified roofer, especially if it is in a difficult position 2. The amount of money I have spent on the "patchwork" could almost have paid for a professional to come and do a proper tie-in to the existing roof. It really is not worth it both from a financial AND a peace of mind perspective. If I never have to put out another bucket during a rainstorm, that will be far too soon! Please consider very carefully how much time, effort, money and frustration you are prepared to put into trying to fix this roof.
  • Wanda McMurray Wanda McMurray on Jan 03, 2016
    Buy roofing tar and tar the flat roof.
  • Phyllis Phyllis on Jan 03, 2016
    it may need a new seal; I would get rid of it and close roof in.
  • Jeanette S Jeanette S on Jan 04, 2016
    Flat roofs are almost impossible to keep from leaking. But keep in mind that leaking can cause rot and a lot of damage much more expensive later on than re-roofing a porch! If you are handy, take off the top layer of the roof (the shingles and decking). Put in some good flashing and build in a slight pitch to your roof. Also, allow for an overhang around the sides and end. Get some experienced advice if you are doing this yourself or call a good roofing company.
    • See 2 previous
    • DJ DJ on Jan 05, 2016
      @Jeanette S Thanks I will.
  • Rebecca Ruge Rebecca Ruge on Jan 04, 2016
    Try Flex Seal, a spray on rubber like sealer...
    • DJ DJ on Jan 04, 2016
      @Rebecca Ruge I thought about that, but didn't know if it actually worked. Have you tried it?
  • Rebecca Ruge Rebecca Ruge on Jan 04, 2016
    No I haven't, but did pick up a can on clearance. Have to wait for Spring now to try it.... too cold here now! LOL! Google Flex Seal, check it out and maybe there is a money back guarantee. If you've found nothing else to work, it might be worth it to try this. There is an official Flex Seal site with three different types of the product, so check it out! Good luck to you!
  • Charles Prock Charles Prock on Jan 04, 2016
    Replacing it and tying it in with the main roof is the only method that will assure it won't leak again...that and doing away with the skylights.....Having built over 700 homes I can assure you that there is not a skylight built that won't leak given enough time and the right circumstances.....Jeanette from Atlanta was correct in saying that rot is going to be a major player here if it's been leaking any length of time....As far as costs for replacing it, you are talking several thousands of dollars. Probably not what you wanted to hear but your home value warrants a correct fix.
  • Mar3393727 Mar3393727 on Jan 04, 2016
    Charles is right on. Hubby is a contractor for residential & commercial Flat roofs hold standing water, need to fix this as it's the best way to END the leaking.
  • LD LD on Jan 04, 2016
    First, water leaks can come anywhere from 25 feet away, and will always go to the lowest point. A residential flat roof is designed to hold a certain amount of liquid, but it is also has a slight slope to it, in order for water to goto gutters and downspout. If you have been having consistent water leaks, you may have water rot, and mold issues. The best thing is to have several expert roofer/builder's come out and look at the current structure, and have them give you a detailed report for cost for repairing and for replacement. For if there is significant damage to the existing structure, it may be cheaper to replacing vs repairing.
    • Toolpro Toolpro on Jan 04, 2016
      @LD You are so right Linda. I had a rental with a leaking flat roof 6' into the room in several places. It only leaked with driven rain from the east.( major clue that I missed) I should have looked at fascia leak, it was behind the gutter. I put a new torch down roof on and it leaked 4 months later. FINALLY my low end handy guy said let me take the gutter off and have a was not good underneath. Coil stock and silicone caulk solved the problem. So yes, yet a variety of opinions.
  • Tom Tom on Jan 04, 2016
    You can try a roofing product from Home Depot called Silconizer. It's an elastomeric paint that is used to stop leaks. Costs about $26 a gallon and is applied with a roller.
  • Mar1416882 Mar1416882 on Jan 04, 2016
    Its is metal?
  • Mar1416882 Mar1416882 on Jan 04, 2016
    Or flashed with a Roof Sealant or Roof coating from Homedepot
  • Toolpro Toolpro on Jan 04, 2016
    My parents had an on going leak with sky lights for about 10 years. The roof pitch is about 5/12. FINALLY they called a roofer. the lights were Pella from 1989 and had plastic curbs that had cracked, nothing could solve the problem until the curbs were replaced and 8 sheets of roofing ply...... Please don't let this go. The problem will only get worse.
    • DJ DJ on Jan 05, 2016
      @Toolpro You know that could be the problem. The porch was built in 1988 so I'll start looking at re doing the whole roof. It's metal and I think it would work better if we just tied it into the house roof and took the lights out completely. Thanks.
  • DJ DJ on Jan 05, 2016
    We are in the process of getting contractors to give us suggestions. Going to tie the roof into the regular roof. Not sure yet if we can do it, waiting to see the suggestions of the contractors. Thanks
  • Cou456440 Cou456440 on Jan 05, 2016
    You could use blueshield!
  • Liliana Wells Liliana Wells on Jan 27, 2016
    For contractors in your area see Put your zip code and project and you will have list of people in your area who can do the joh. Good luck.
  • Jennifer Jennifer on Mar 07, 2024

    I advise you to choose Butyl MS Caulk that is an ideal product for this purpose. It is a cost effective, durable and long-lasting product. It has high adhesive features and works very effectively on all kinds of roofing materials. It can be applied at low temperatures, has quicker dry time and a state-of-the-art hybrid polymer chemistry designed to withstand severe climate, weathering, and environmental conditions.