Calling all contractors....Is it possible that houses can sweat or could my roof be leaking?

Yes, houses sweat, espically in the summer on these hot humid days. The inspection is a great idea, just make sure the guy is reputable.. Any moisture traped in a house will cause condensation, ex; damp basements. This can also lead to mold, so I strongly recomend a dehumidifier. Now moisture traped between wall and in insulation is a bigger problem. Houses also need to breath so this moisture will not stay traped and lead to mold problems. I would need more details and a peek but this may sound like part of your problem and this is somthing you do not want to spread. Check to make sure this is the only area where the moisture is visable, check the rooms above and below.. In areas where there is alot of storage seperate items and boxes so they are not all piled together. Use moisture absorbing packs, usually found at home depot and such-- They are like the little things in your shoes but on a larger scale.. Use dehumidifiers and spen few bucks for a good one--Check consumer reports. These little babies could save you thousands down the road.. Always check the refrences of contractors and shy away from lettiong a "FRIEND" do the work. Unless you check his refrences also and are willing to loose the friendship.. Sadly there are alot of sheenies out there giving bad names to us reputable contractors.. Though my expertise is electrical, you get to know a little bit about everything in the trades.. Good Luck

Water is very logical in its' own way. I believe, as you do, that there is a connection between the recent driving rains and the marks on your wall. For water to enter the home, it has to have an access point. Because water can travel a considerable distance after penetrating a roof or wall system, that point does not have to be at or near the site of the problem.

If I am trying to analyze the source of a leak, I try to think like water. It generally rolls along, minding its' own business, until stopped by an obstruction, such as a flashing joint or vent. The first thing I would do is carefully examine the roof in the area above and higher than the marks occurred for a suspicious flashing or vent that showed signs of retaining moisture (mold, bits of debris, dry rot, rust, structural damage)

If it all looked good on the roof, I would imagine how a laterally-driven rain might find its' way to the spot; perhaps through a soffit, opening in a fascia board, or top of a window.

Once you have spotted the culprit, the best sealant that is readily available is Pro-Series Quad urethane caulk available at Lowe's or Home Depot. Pick a color that matches the surrounding material best, and apply on a clean surface, prepared by wiping down with mineral spirits. Work the material in with your finger for a good seal.

You will ultimately be very satisfied to successfully diagnose and treat your mystery residue.

If the marks were dried out "drip" marks the causes may be one of many, particularly if this is an outside wall:

It could be simple condensation -many houses from the 60s onwards were built with inadequate ventialtion. If you or previous occupants have dried clothes on radiators, cook with gas or use free-standing gas heaters (whose fumes include water vapour), then the upper angle part of a cold outside wall is just the condensation trap where you might have had droplets forming and then drying out.

The main thing is that you have wiped the marks away and can now look for their re-appearance.

If there was water dripping in from the roof or flashing, you would be able to see holes or cracks where the water had trickled in. What is outside this area of the wall? A chimney? Guttering, roof flashing? (Flashing is the lead or similar metal applied to give a waterproof seam where there is a join between a wall/chimney and a roof. If it is damaged or mis-shapen it can allow water to penetrate. Are there any pipes in the wall or water tanks in the loft above the marks?

Even if there was something allowing damp to penetrate the wall, without a crack or hole for it to come in by, you would get a rounded, fuzzy damp patch, with a "tide mark" stain round the edge. The fact that you have drip marks makes this seem unlikely.

Have a look up in your loft. First see if you can see any daylight coming in through the tiles! If you have a skylight which you can open, try sticking your head out for a look around. Don't go on the roof -not only is it dangerous, you risk damaging it by walking on it! You'd be surprised how much you can see from standing in a skylight, or even from the ground with binoculars!

If you get a builder or roofer to have a look there is a 50/50 chance that you will be overquoted. There is not much roofing repair work going on, so he will be happy to spend two hours reading his paper on your roof and charge you £600 for clearing the guttering, or taking a tennis ball out of the downpipe! Get three quotes from people who have been recommended to you.

My neighbour has damp coming in her bedroom wall and it is obvious from the ground that the guttering is cracked and needs repaired just where she has the problem. There are stains on the outside where the water has been trickling out and the mortar pointing on the stone work is damaged. One builder told her she needed the whole wall taken down and rebuilt! Obviously someone having a quiet summer!

Is there any damage or cracking on the outside of the wall? If you think that there might be damp coming through from inside the wall there are simple handheld probe devices which measure dampness in brickwork, plaster etc. Many surveyors use these and they can be bought in DIY stores.

The intriguing thing to me though is that you thought that these marks were "sweat" marks. This would indicate condensation to me. The key to beating this is firstly, minimise anything which puts water vapour into the air (see list above) and, secondly, try to remove it by ventilating properly. "Dead" corners don't let air circulate. This is why you get mould in the corners of shower rooms etc. Open windows, even a crack, use the little vents at the tops of the window frame. Fit an extractor fan in the kitchen window.

I had a flat where we had a bit of a condensation problem in our bedroom. I guess that we sweated while we were sleeping and, due to the design of the place, two and a half of the four walls were outside facing walls. My neighbour below never used the room under us so it was never heated, making the walls colder still. Previous owners had lined the walls with a polystyrene insulating paper, about an eighth of an inch thick, and this helped to prevent condensation a bit, but we still got it in the "dead" corners. There was normal paper hung ontop of this lining.

We used to joke that our bedroom was haunted, because it was so cold, until we found out that the old woman below only lived in one room!

Is it possible that they are stains from some liquid which was spilt or sprayed long ago and not cleaned up properly? Kids with juice, bottles of pop etc can make a mess and maybe whoever cleaned it missed a bit if they couldn't reach!

Good Luck!

Roof "sweating" could be due to condensation problem as you mentioned "strangely strong rains recently + extreme heat". Try waiting for a few days when such weather goes back to normal and see if the problem persist. If still do, contact an inspector to check your roof as there may really be leaking problem.

Hi,

Unfortunately, you don't say what material the drops where on, which would have been useful. It sounds like condensation to me. Roof leaks usually manifest as damp marks rather than drips but it is hard to diagnose without more information. You can ignore 'rising damp' since it is at the top of your walls.

I think I would crawl up in the attic the next time it rains to see for myself. If you have a corrugated roof it is possible it could be sweating, but that would almost always happen in the early morning. A wood and shingle roof will not sweat like that.

Beacause they named the orange first. And in case you think of roughly it in the event that they names all fruit after there coloration think of what a farmers marketplace could be like " Eh! i've got been given some super yellow and a green and a orange" guy or woman calls out "The orange vegi or the fruit" see it might basically get messy

yes a house can sweat. it sound like you have a ventilation problem,you need to run your bathroom fan longer. also if you have a ventilation system turn it on, or up. if not.leave 1 or 2 windows open just a crack and run the bathroom fan for long periods of time

What is the history of the house?? is it old?? and if so maybe there is the presence of something un-wanted ie ghostly nature. Good Luck :) OR Maybe there is a little critter living in that corner urinating every so often??

If there is a dead body in the wall of your house, it may be rotting and the body juices may be seeping through the wall.