Is my roof leaking?

May 9, 2008 8:46 PM

There are ceiling-to-floor water streak marks in one of my bedrooms. Is this just condensation or could it be a roof or wall leak?

Everything I've read about roof leaks refers only to ceiling stains and non-streak wall stains; and water streaks seem to be associated with condensation. Condensation is a possibility in this room since there was a humidifier running in it over the past few months, and there are some signs of condensation -- also streaks -- on the wall directly above where the humidifier was located. But these worrisome streaks are on an exterior wall; they are much more noticeable, and are longer (ceiling to floor) than the ones near the humidifier. They are about 6 inches wide at the top, tapering down toward the floor. Could the streaks be a sign of the underlying studs being soaked and seeping through? Or could it just be condensation caused by the humidifier?

Perhaps it is relevant that it has been raining for two days, but on the other hand these streaks might have been present longer and I only just noticed.

My roof is 4 years old.

posted by ellenaim to home & garden (6 comments total)

Not a contractor or home inspector, but speaking just as a homeowner: If this were happening in my house, I'd be freaked out enough that I would grab a 1/2" drill bit and drill some test holes in the wall, just through the interior layer of plaster/sheetrock/whatever to see if it was wetter on the other side (holes large enough to see/feel through, but small enough to spackle over easily afterwards). Water damage is Bad News; if it's happening, you need to know now, and I'm not sure there's anything someone could tell you over the internet that would be reassuring enough.
posted by range at 9:48 PM on May 9

I've lived in houses that seemed to attract a lot of condensation with no extraneous problems, but you really need to call a contractor or inspector to tell you for sure. Check around and make sure you pick someone with a good reputation (not a fly-by-night service that might be tempted to exaggerate your problems for an easy buck).
posted by amyms at 10:28 PM on May 9

I lived in a rental house years ago that had an attic that had not been properly ventilated. The vents were in place, but the contractor had never cut holes in the wood behind the vents, so they were really just decorations. Water accumulated in the space above the ceiling, and eventually oozed out and made a gigantic sticky mess. The whole ceiling had to be removed, the area dried out over several weeks, and the ceiling replaced (after the vents were properly made).

So, I'd suggest you look into the possibility that your ceiling space isn't properly vented. Not knowing what kind of ceiling you've got, I can't tell you how to do that. I'd probably call a contractor myself.
posted by Capri at 2:53 AM on May 10

I'd look into the possibility that leaves are blocking up your guttering. That's generally what causes the rain to pay a visit to the interior of my living room.
posted by flabdablet at 2:58 AM on May 10

The profile of the roof above the bedroom will give you a clue as to where the water may be coming from. Does the roof slope downward toward the wall with the water spots? In other words, if you were standing in the attic above the room in question and facing the wall with the water streaks, would the rafters be sloping downward from behind you and meeting the attic floor in front of you? If so, water leaking through the roof will trickle downhill along the rafters and sheathing (the plywood covering on your roof to which the shingles are nailed) and then down the wall in your bedroom. Before drilling holes in your walls, try going up to the attic and see if you can see wet wood or water stains on the underside of the roof. Tracing those stains uphill will take you right to the leak(s).
posted by dinger at 5:41 AM on May 10

Condensation is just as bad a sign as a leak, as it indicates woefully inadequate insulation. This is home inspector territory, and you can find a good local inspector at the American Society thereof.

You can usually get a single-item inspection, but since you're really paying for the inspector's time which includes the drive out and back, getting a regular inspection makes good sense. You'll learn a lot, and future maintenance will be much easier with that knowledge in hand.
posted by Myself at 8:18 AM on May 10 [1 favorite]