How to FIND an exterior house Leak?

Jim Ginas
by Jim Ginas
had a Sunroom Addition and since, we have had a leak. Obvious assumption is it is where the Roof of the sunroom meets the house. I can hear the leak, as water droplets are hitting the top of the fireplace inset. I've walked the roofline to look to see any obvious spots where the flashing might be the issue. ** I did find a corner brick to a far end window that is cracked and looks like rain water could seep in there. (Will silicone caulk that when it dries up outside. --- BUT is there a means a moisture meter or something could pinpoint where the water is coming in from?
  9 answers
  • KMS Woodworks KMS Woodworks on Nov 13, 2012
    Bricks and flashing are always tough to get sealed. Caulk would not be the best...I would steer more toward a "through the roof" type sealant. Once leaks get into a wall or ceiling it is tough to track them...they tend to run along the back if the drywall and can often be feet away from where the effects are first spotted.
  • Infrared camera can spot the water location and path. You can also use a infrared thermometer to look for temp differences, but that can be a bit harder to do. Water can enter from the strangest places and often do not come from where your thinking it is. If there is a change of roof pitch, or where a roof meets a wall, that is always the first place to check for a leak. If the flashing was not properly sealed against the house behind the wall and behind the house wrap, the water can be getting in from behind there. I have had leaks in some homes where the leak was coming from a window in the upper level of the house, traveled between the spaces and joints in the plywood sheathing ending up leaking in the basement still. Not knowing your homes layout it is impossible to give you ideas on where to leak. Photos of the roof, walls and area where leak is occurring can help a lot.
  • Jim Ginas Jim Ginas on Nov 13, 2012
    @ KMS: thanks, I'll look for "through the roof" at Lowes, @ Woodridge: ok, I'll wind up calling in a roofing contractor (i'll check if they have Infrared cameras before hiring them) an ask them to find and fix the leak. Thanks much.
  • This is what you are supposed to be seeing in regards to the correct flashing detail Where the flashing meets and lays over the top course o shingles the contractor can cut and glue using asphalt cement a shingle to hide the flashing, but the roof shingle that is offering the protection of water proofing must be under the flashing in order for it to work.
  • Nora Nora on Nov 14, 2012
    Ugh, I hope you find it fast, Jim!
  • Jim Ginas Jim Ginas on Nov 14, 2012
    Hi Norah! Its strange, we had it during last year's hurricane, then nothing really unless we had heavy sideways driving rains. This past month, although we had heavy rains, they weren't significant enough that we should have heard the water, but we did and this past rain wasn't bad at all, yet it happened again. I am hopeful to get this worked in the next week or so.
  • KMS Woodworks KMS Woodworks on Nov 15, 2012
    most leaks get worse with time...the failure may start as some simple caulk cracks...then end up with the caulk falling out. I have seen this too many times.
  • Jim Ginas Jim Ginas on Nov 15, 2012
    KMS: you are exactly right! It started as only in the worst driving rains, and now with just a typical rain, we hear it. I've been working 14 hour days this week, and will have to use tomorrow to try and 1) seal a crack in a brick near the window and 2) caulk around the glass and frame. (painters Powerwash today on exterior and when they hit the windows, it happened again. THEN if not, I have to find a contractor with that Infrared camera!
  • KMS Woodworks KMS Woodworks on Nov 16, 2012
    good luck...I know how frustrating it can be...looking for the proverbial needle in the haystack