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WATER ENTRY IN BUILDINGS
AGE of MOLD - Old is the Mold?
BASEMENT CEILING VAPOR BARRIER
BASEMENT MOLD WATER IMPACT
BRICK WALL DRAINAGE WEEP HOLES
BUCKLED FOUNDATIONS due to INSULATION?
BUILDING DAMAGE ASSESSMENT & REPAIR
CONDENSATION on WINDOWS & SKYLIGHTS
DEW POINT TABLE - CONDENSATION POINT GUIDE
EFFLORESCENCE, Salts & White / Brown Deposits
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOD DAMAGED FOUNDATIONS
FLOOD VENTS & FLOOD PORTS
FLOODS IN BUILDINGS-mold
FLOOR DAMAGE DIAGNOSIS
FOOTING & FOUNDATION DRAINS
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION CRACKS & DAMAGE GUIDE
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
HUMIDITY LEVEL TARGET
ROOF ICE DAM LEAKS
MOISTURE CONTROL in BUILDINGS
MOLD INFORMATION CENTER
NOISE / SOUND DIAGNOSIS & CURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
SEWAGE BACKUP, WHAT TO DO
SEWAGE BACKUP TEST & CLEANUP
SEWAGE BACKUP PREVENTION
SEWAGE PUMP CLOG DAMAGE
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
SWEATING (CONDENSATION) on PIPES, TANKS
TOILETS, INSPECT, INSTALL, REPAIR
TRAPS on PLUMBING FIXTURES
VAPOR BARRIERS & CONDENSATION in BUILDINGS
VENTILATION in BUILDINGS
WATER ENTRY in BUILDINGS
WINTERIZE A BUILDING
Wet or damp basement cause, diagnosis, cure & prevention: this article describes visual inspection methods and clues to detect basement leaks, water entry, flooding, or just high moisture problems.
Finding where basement or crawl space water is coming from is the first step in fixing foundation leaks and wet basements. Here we illustrate common basement water entry leak points and signs that can be seen from inside the building.
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Wet Basement Diagnosis: a Guide to Inspecting for Basement Moisture, Leaks, Flood History, or Chronic Water Entry
[Click to enlarge any image]
Image at left provided courtesy of Carson Dunlop Associates.
A clear answer to where basement leaks originate avoids falling prey to the rising ground-water or there's a stream under the house fib that sometimes leads homeowners to installing an expensive fix for the wrong problem.
Where to Start Diagnosing Building Water Entry & Wet Basements - Outdoors
In this article we begin with a catalog of basement or crawl space water entry signs seen from inside the structure. Our opinion is that an expert inspection for a building basement or crawl space water entry problem begins outdoors with an inspection of the site, roof drainage, and similar features (see EXTERIOR WATER SOURCE ELIMINATION). But there are plenty of indoor clues of water leakage problems in buildings, and they can be found on every level of the structure.
Is Your Indoor Moisture or Water Problem Rising Damp, or do you have Basement or Crawl Space Water Entry Leaks?
Basement trim water stains can be a good indicator of a history of wet basement floors. In our photos below we illustrate a cute attempt by someone to "hide" the water stains on basement door trim by placing little stuffed animals in the doorway. First the skunk, then the little squirrel happened to tip over, disclosing that the little rascals had been hiding water stains.
3 Levels of Basement "Wetness" - Inspecting in the Basement for Sources of Building Leaks or Moisture Appearing as Attic Condensation
3. Flood conditions in a building: water extends over the entire building floor, extending from a fraction of an inch to virtually filling the building and even flooding upper floor levels if a building is located in a flood plain or flooded area.
At below left our client points out that basement flooding had reached at least this far up from the basement floor - leaving mud on the bottom of an expansion tank. In this neighborhood we also found flood-deposited mud atop sill plates at foundation wall tops.
Our second photo, at above right, is really an outdoor clue, though you might see this from the inside: it's a foundation flood vent, indicating that the builder thinks the building is in a flood prone area.
Our second structural rust photo (above right) was very exciting. We were inspecting a house on Long Island when the owner mentioned that she had pumps running 24/7 in the basement to keep the bay at bay. All of the Lally columns (some were just hollow pipes not real Lallys) were badly rusted. Details are at COLUMNS & POSTS, DEFECTS. Also see FLOOD DAMAGE TO FOUNDATIONS. For problems with settlement of piers below Lally columns see Settlement Cracks in Slabs.
Our photos below are clear examples of a severe basement flood. If you inspect closely you may find multiple apparent high-water lines on basement surfaces or contents. Don't assume this is necessarily multiple flooding events. The lines may be multiple separate events, or they may be stages in lowering of the water level in a flooded basement. Additional clues (such as rotted floor trim) can distinguish between a one-time basement flood and recurrent water entry.
Our second photo shows our inspection client taking a break next to flood lines on a warm air furnace base.
More basement water entry clues: details on walls
Concrete Foundation Wall Leak Points - Leaks at Cold Pour Joints
At COLD POUR JOINTS, CONCRETE we discuss the cause and possible significance of cold pour joints on a poured concrete foundation wall. Usually a cold pour joint in a concrete wall is only of cosmetic import. But if sufficient time elapsed between successive concrete pours into an individual foundation wall, the lower wall concrete "sets up" enough that there is a poor bond between that layer and the next pour of concrete into the wall forms.
The result can be not only a visible "crack" in the poured concrete wall, but this cold pour joint may leak surface water or ground water into the building. Our photo (above left) shows white efflorescence stains left by a long history of building foundation leaks at a cold pour joint on this building.
Also notice that in the corner there was some efflorescence above the cold pour joint, while at the second photo (above right) there was efflorescence and leakage only below the cold pour joint. At both of these locations a roof drainage downspout had spilled water against the building wall for many years.
Our photo (below left) shows a normal concrete floor slab shrinkage gap where the floor (under our pen) abuts a poured concrete foundation wall.
The brown material on the floor is mud which we suspect rose up from below the slab when surface runoff or ground water saturated the soils around and under the floor slab.
Our second photo, above right, shows minor seepage through the concrete foundation wall at cold pour joints. Most cold pour joints are not leaky, but this one was.
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Our home page for diagnosing and curing foundation leaks and wet basements or crawl spaces is WATER ENTRY in buildings. If your building has been flooded, see FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.
Frequently Asked Questions (FAQs)
Question: how to diagnose the cause of ceramic tile failure over a wet floor or crawl area
I have just been looking at your article on wet basements and noticed the photo you have curling, lifting floor tiles . I have just experienced the same problem whereby about 50% of my ceramic tiles slowly started to have a hollow sound when knocked. I removed them and found all the tile glue attached to the bottom of the tile, and the same pattern was left behind on the concrete floor of where the tiles have been.
The tiles were laid 2 years ago. Also when lifted the tiles were moist and the gout lines left on the floor seemed to be softer than the rest of the concrete. There originally was a raised wood floor in my apartment when I moved in, but two years ago it started to rot and buckle.
My insurance company took a look and found that a un-insulated hot water pipe feeding water to the apartments above was running under the floor and was the most probable cause, pulling ground water up and turning it into steam ? The pipe was replaced and insulated, and I was told that the best thing for me to have on my floor was tiles, and floor heating.
So I had a plumber install a hot water floor heating, and had about 2-3 cm of self leveling concrete poured over it. The guy who poured the self leveling concrete told me that it will be ok to lay tiles in 7 days or so, which I did and turned on the floor heating several days later.
The thing is, many people are telling me the problem is I didn't wait long enough for the self leveling concrete to dry properly, and if I clean and re prime the floor it will be good. But I am worried that the floor heating is creating the moisture and the same problem will happen again. Can you please give me some good advice. It has been suggested that I turn off the floor heating and replace just one tile and if after a few days it remains firm it will be safe to proceed to lay the others ? But I am very wary, and cannot be sure what to do ? I hope you will reply with some good advice.
A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone. You will find additional depth and detail in articles at our website. That said I offer these comments:
Frankly I think your insurance company was barking up the wrong tree. An uninsulated hot water pipe won't place water in a floor structure (unless the pipe is actually leaking), in fact it would have the opposite effect: it's heat would cause things to be more dry than ever. Really I am a bit embarrassed to have such a strong reaction to a question but I can't make any sense out of the diagnosis you received. It sounds like wild arm-waving. Or somehow I have completely misunderstood your question.
For a hot water pipe to cause other ambient moisture to flash to steam we'd have to be heating the water to over boiling - over 212F; A domestic hot water pipe should be running no more than at 120F to avoid scalding and comply with building codes in most areas.
You have a water source (I don't rule out ground water if the floor was not properly built), or pehaps an actual leak somewhere. An uninsulated COLD water pipe could drop condensate into a floor structure but enough to cause rot in just two years sounds unusual to me. I'd look for some other leak into the floor.
About curling floor tiles - that occurs with vinyl type floor tiles installed where the floor has been wet from leaks from any source; ceramic tiles don't curl; But they might indeed come loose if the floor and subfloor are wet;
More information about how the floor was constructed, and the crawl area conditions below the floor, are essential to make sense out of this question; meanwhile I suggest that you do not do anything costly by way of "repairs" before we are confident that we understand what the heck is going on.
Thank you ever so much for your speedy response, I am including 2 photos of what the floor looks like after I removed the loose tiles. I think the issue is definitely ground water,as the house was built in 1929, and although the sewage pipes have all been renewed, the rain water drain pipes that go around the exterior of the building are the original concrete ones. I have been told that they should be dug out and new plastic ones put in deeper down that are perforated in a way that will collect the ground water and prevent it going under the house. But as it stands at the moment the other 5 apartments that are above mine are reluctant to get them repaired because of the cost.
I had a building inspector round and he told me paint the floor in the adjoining bedroom where the damp readings in the floor are highest with a damp proof material before I lay the tiles . As for the living room floor where the tiles have come loose,the damp readings are quite OK ( but I am wondering if it is not because I have heating in the floor?)
The inspector has told me to use a better tile cement than I used previously and just replace them.( I think I would be more comfortable painting this waterproof primer on before,but it is about 2mm thick, so there will be a discrepancy in height with the rest of the tiles that are still strong on the floor.)
As I said before, when I removed the loose tiles all the cement was stuck to the bottom of the tiles with little or none on the floor.(Although the tiles that remain down seem to be strong enough?) Also they were slightly damp when lifted.
Several people believe the reason could be that I put them down without allowing sufficient time for the self leveling concrete to dry (it was about 2-4cm thick, and I laid the tiles after aprox 7/8 days almost 2 years ago) ,and that the residue water from the concrete got trapped under the tiles unable to evaporate?
Or that I turned the floor heating too soon, or too high too soon? A tile specialist has recommended that I just put one tile back to start with, then try and get it free in a few days after it has set. He said if I need a hammer to break it loose it will be safe to put the others back. I will be looking forward to your reply Daniel, meanwhile I have the tedious task of scrapping back the glue from the lifted tiles .
Originally you said "There originally was a raised wood floor in my apartment when I moved in, but two years ago it started to rot and buckle" but It's not quite clear to me how your home was constructed and whether we are talking about a wet damaged tile floor over a basement, crawl space, inaccessible crawl area, or slab on grade. That detail would help determine how best to inspect the water damage problem.
Regarding the rain water drain pipes that go around the exterior of the building are the original concrete ones. I have been told that they should be dug out and new plastic ones put in deeper down that are perforated in a way that will collect the ground water and prevent it going under the house.
While clearly someone corresponding by email can't be as properly informed as an onsite expert, this advice does not sound correct to me. First, if the roof drainage system is properly sloped it does not need to be deeper nor below the frost line.
Second, we never want to tie the roof drainage system into the (much deeper) foundation or footing drain system - it sounds as if your advisor may have been confusing those two systems. Doing so overloads the footing drain and invites water entry through the foundation near its bottom;
Third, we do not want to put perforated roof drainage system pipes close to the house to carry off roof drainage. Doing so invites foundation leaks. Rather that water needs to be delivered to daylight well away from the building where it won't return, or delivered to a storm drain system if local codes permit that approach.
Fourth; an old, "original" roof runoff handling piping system is very likely to have clogged or failed by now; if those original drains come to daylight it's easy to see if the drains seem to be working; if the drains do not come to daylight nor to a storm drain, then they are not working.
About the leveling compound dry time: I don't know the if tiling over wet cement was the original problem: tiles would have come loose early after installation, and more, opening the floor years later would not show wet conditions; if you found wet conditions two years after an original tile job, there was a current water or condensation source.
About priming the floor as a "fix" for a prior tile job failure, that advice sounds a bit inadequate as a solution to a floor built over a wet area or a damp surface; you would be relying simply on a thin coating of primer to keep water out of the floor structure, after already allowing it into the subfloor where over time you risk rot, insect damage, and floor disassembly.
The proper approach is to find and fix the source of water entry. While on occasion there is indeed a ground-water problem at a property, experienced home inspectors and honest basement waterproofing contractors will tell you that 90% of the time or more the problem is not "rising damp" and not "ground water" but rather mis-handling or inadequate handling of roof runoff or surface runoff around a building.
In sum, my view is that it would be a mistake to repair the evidence of a water problem (loose tiles, damaged floor, wet crawl or under floor area) by replacing finish flooring before the cause of water is correctly diagnosed and cured.
Questions & answers or comments about how to determine the extent and history of basement water leakage at a building.
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