Wet or damp buildings, basements, crawl spaces: questions & answers about cause, diagnosis, cure & prevention:

Diagnostic questions, answers, & photographs help analyze clues indicating the history of building leaks, water entry, or condensation.

This article series describes visual inspection methods and clues to detect water entry in buildings, indoor condensation, high indoor moisture, water damage, basement leaks, water entry, flooding, or just high moisture problems.

Building Water Entry, Moisture, Condensation & Wet Basement Diagnostic FAQs

These questions and answers about dealing with wet basements were posted originally

at BASEMENT LEAKS, INSPECT FOR - topic home. Be sure to see the advice given there.

On 2019-09-16 by Sg

Is this concrete basement wall foundation a problem? What is this? Does anyone know. Please advice.

 

Reply by (mod) - cold pour joints may be just a cosmetic concern - if not leaking

Sg

please use the. search box just about to search inspectApedia.com for our article titled

CONCRETE COLD POUR JOINTS

In concrete foundations to read a description that probably fits the concrete foundation wall in your photo. Take a look at that and don't hesitate to ask follow-up questions as needed

What's the best way to find the exact source of basement flooding during heavy rains

Is there a way to successfully determine the exact source of basement flooding during heavy rains

live in a city - house is from the early 1800 brick exterior with neighboring homes on either side

I've lived here for 19 years with no basement water issues until 4 years ago ... since then I've had basement flooding (only during heavy rains ... the neighboring homes do not have flooding issues)

It only happens during heavy rains (starts immediately and stops as soon as the heavy rain stops - water is clear but once the water was brick red after neighbor had chimney work and once it was muddy)

- if we had 2 inches of rain throughout a 8 hour span of time there would not be water in the basement

- if we had 2 inches of rain in one hour there would be basement flooding

- water started to appear in the hearth of the basement fireplace (north side of the house) and has spread along the entire north basement side

- flooding still happens when the exterior north wall is dry during a heavy rain

I've done all sorts of repair work in hopes of resolving the problem (all with NO results and still unable to determine the source of the rain water leaks):

replaced roof/gutter/downspout/cricket behind chimney
added chimney cap
video scoped the my sewer line (which is on the south side)
checked north exterior brick wall
checked north neighbor's basement/sewer line
basement waterproofers inspected for source of leaks
(they could not determine the source and pushed for a french drain)
PWD inspected for the source of leaks

I hate to keep spending more money and install a french drain and find out it's some building structural problem or something else

I need to find someone who can determine the actual cause and go from there ... do you know if here is a way to actually test/inspect and determine the actual source

Many thanks in advance for help in solving thismoisture gradients over finished surfaces - On 2018-12-23 by SMT

Reply by (mod) -

SMT

Usually we can spot the source of basement water entry by a combination of indoor and outdoor inspection by an expert who can recognize sometimes subtle clues like drip lines under gutters, damaged downspouts, in-slope grade, old failed foundation drainage, and inside by tracking water stains and measuring moisture to the most concentrated areas.

Part of the cause of exact point of water entry can be buried such as anomalies in the density and contents of foundation backfill and the location of ditches dug to the foundation to bring in or out mechanicals such as wiring or piping.

More causes and cures are at WET BASEMENT PREVENTION

More rare are leaks in sewer lines near the home or water pipes entering the home.

On 2018-12-24 by SMT

Thanks for the reply

Question ... would groundwater or underground stream be clear water and start/stop at the exact same time as a heavy rain ?

Is there a way to actually find the source of the leaks and what type of a contractor/inspector does that type of service (since no one has been able to help so far)

Should the inspectors/contractors have a special type of certification/licensing ?

Can the water be tested determine the source ?

Do you know if infrared-thermal-imaging works ?

MANY thanks again for your help

Reply by (mod) -

SMT

There are often delays, as much as days, between heavy rain and water entry related to that rain, as depending on site and soil conditions it can take time for water to infiltrate through soil to and through the foundation, slab, or footings into the structure.

The chances that there is an actual "underground stream" causing water entry are small. It's rare for a building to be constructed with its lowest level below the local high water table - usually that's discovered during excavation and during the permit approval process in the first place.

An experienced home inspector ought to be able to help you. ,See the page top EXPERTS DIRECTORY on any of our pages.

On 2018-12-25 by SMT

Thanks for the reply

Good to know ground water takes time to appear


My issue is timed exactly when there is a heavy rain (starts and stops with the heavy rain)

We have been told there are underground streams in the neighborhood, an early section of Philadelphia (maybe they are just old wives tales)

if it was underground water would the water be clear?

I've already had a building inspector, many contractors, basement waterproofers, the Philadelphia Water Department check for the source of the leaks ... none of them were able
to determine the source of the leaks

... will check your experts directory

Thanks again

Reply by (mod) -

You cannot make any assumption about the clarity of underground water when it leaks into your home.

Not always, I admit, but most of the time when I find a building water entry problem the water came off of the roof and was not being properly directed away from the structure.

 

What tools can we use for a "quickie" inspection to find out where water leaks are coming from?

Regarding the inspection and repair of leaks in cellars:
What kind of tools are used for the inspection next to humidity meters?
Is more area excavated than required based on conservative estimates(% of the cases)?
Is there any need for quick inspection tools to find out where the water is coming from?O n 2018-07-23 by Stefan

Reply by (mod) -

Sorry I'm ovewhelmed by the question. What problem are we solving here?

No TOOL is a substitute for an expert and thorough visual inspection inside and outside of a building when diagnosing the cause of leaky basements, cellars, crawl spaces.

But you can use a moisture meter to trace levels of moisture to see where the moisture is greatest.

Watch out: there may have been prior leaks and very costly damage in areas that are dry now - so a moisture meter will miss those problems.

No home inspector excavates or digs in that initial inspection and doing so would not be a "quick inspection " approach.

Inspectors might supplement visual inspections with use of several types of moisture meters to look at

New Home Construction halted: wet, leaky: what do we do to prevent more damage?

We are building a lot home. We have basement poured and enclosed on walkout end.

We have subfloor on top and half the logs up. At a stand still at moment and basement leaks from subfloor above.

How to deal the subfloor from leaking and to keep it from deteriorating until we can get roof on. - On 2017-03-25 by Tina

Reply by (mod) -

Tina

Aaah you are building a LOG home not a lot home - don't you love how your spell checker changes what it thinks you should say?

What do you mean "basement leaks from subfloor above"

If you mean that you've not got walls up and roof on - ie you're not yet at "dry-in" and that rain or snowmelt leak into the basement,
usually we live with that, drying the building out AFTER Dry-In is complete (that is the weatherproof shell is complete)

Watch out: do NOT let someone bring in and store anything that will be ruined by getting wet - like drywall or insulation.

I worried that my subfloor would buckle when it got rained-on. It was glued and nailed down. It didn't move.

Please use the page top or bottom CONTACT link to send me some photos of your wet basement, wet subfloor, and views that show where you are in construction.

Also we have a sickening amount of info on log homes but I particularly would like you to look at and comment on LEAK DIAGNOSIS & CURE in LOG HOMES at https://inspectapedia.com/structure/Log_Home_Wall_Leaks.php since there you'll see some details that you can get right during construction and that will avoid leaks later-on.

Also see https://inspectapedia.com/structure/Building_Dry_In_Definition.php where we'll post your helpful question and my speculative reply.

Question: White deposits & Rust on surfaces in a Hurricane-soaked Florida home: corrosion, water entry or leak history? White paint?

I am looking at purchasing a house and the inspector found quite a few areas in the attic on metal strapping, A/C Venting and light cans that had a white corrosion on it.

In addition [white deposits and rust were visible ] in the fuse box.

I am trying to decide if I should move forward with the house and ask for a reduced cost for repairs or stay away from it completely.

The House is in Florida slightly north of Orlando. It was built during the possible “Chinese Drywall” time however the inspector does not think this was the cause. The house did have some water issues in a wall of the house at one point and might still have one which we would take care of but they are block walls not wood.

Here are the images the inspector sent me.

Can you tell me what the next step is I should take or if you have seen this and can offer any quick info? Thanks, - Anonymous by private email 2016/08/12

Reply by (DF): opinions interpreting photographs of rust, paint, water stains in a Florida home

With the apology that an on-site expert will always see important diagnostic clues that won't be in anyone's photos, what I see in the photos makes me suspect the following:

1. This house has had a very wet or damp interior ranging no less than from where the panel is located (in FL I presume there's no basement so I figure first floor) up into the roof space. I see rusted armored cable (BX) at those light fixtures. [Above]
   
   I also see blown-in cellulose insulation that seems to be pushing its way into the light fixture and I don't see a metal strain relief at the wiring passage.

1. I see rust around the knockouts in the electrical panel and rust on the panel face knockouts telling us of a history of high moisture or water in this area. [Below]

I also see rust stains on the top of a circuit breaker indicating that this or these breakers have been wet.

Watch out: in my opinion the electrical panel and thus service in this building is unsafe, risking fire or shock as rust and water-damaged circuit breakers may not trip when they should in response to an overcurrent.

1. It's possible that some of the white deposits you see on metal, such as metal strapping, could be corrosion on galvanized metal - also related to water or moisture levels in the home.
   
   Below in one of your photos we can also see what looks a lot like water marks on the upper side of a ceiling joist to which strapping was nailed. I can't say if this was from a roof leak, water blown in through a soffit or roof eave, or dripping from high condensation levels.

1. I see white paint overspray inside the electrical panel - there is little doubt of this; if you look closely at the photo of the upper-under-side of the electrical panel you'll see some elongated white droplets that indicate the direction of spray paint movement.
   
   While other white deposits such as on the pot lights and strapping may be corrosion, this is paint.
   
   The walls around the panel were spray-painted while the panel cover was off. Also seeing this deposit on the top of bakelite or plastic circuit breaker surfaces suggests the same as those aren't metal surfaces that rust.

but

Watch out: I also see rust around those electrical box knockouts - more evidence of wet electrical components.

A circuit breaker that has been soaked is unsafe - it may not trip when it should in response to over-current, thus risking an electrical fire.

and below we see this white stuff atop circuit breakers in the elecrical panel -

See CORROSION in ELECTRICAL PANELS

1. It is possible that the white spray was applied to cover water stains, rust, or mold in the home.
   
   While there it looks like corrosion on the pot lights, the fact that there might be some spray paint or fungicidal sealant in the attic too would expand that area of work. Look more closely around the attic side of those pot lights to see if any paint is present under the insulation.
   
   A close in-field inspection ought to be able to make a confident distinction between white spray paint or sealant and white mineral salts or metal salts left from corroding galvanized metal.
2. Knowing the age of the home and its leak and water history would help.
   
   But looking in the electrical panel at the wire labels and around the panel I saw some rather shiny surfaces; these two items could suggest that the panel bus was actually replaced. That might have been done following water damage.
3. Check public records:
   
   I don't know Florida's rules on this but if a home has been subject to storm damage, insurance settlement, and repairs, it'd be helpful if there were a public record of that as that would let you know just what repair work was done - what was its scope.
4. Watch out:

• Beware of: previously-wet, mold-contaminated building insulation.
• Beware of rust/water damage in electrical components, particularly circuit breakers that might due to corrosion not trip in response to an overcurrent: a fire and shock hazard
• Beware of moisture-related insect damage
• Beware of hidden mold reservoirs in the building. Find the most-suspect area and investigate therein.

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.

Reply by DF:

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 perhaps 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.

Reader Follow-up:

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 approx 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 .

Reply:

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 mishandling 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.

Question: is it good to use liquid rubber for waterproofing basement walls?

Simon said:

Honestly,I have a bee in my bonnet about trying liquid rubber for waterproofing my basement walls.

It proved to be an excellent remedy for sealing roof. Would you recommend these basement waterproofing products .

Reply: Not Really

Coatings on a wall interior may stop dampness but long term performance where there has been actual water entry - I'm doubtful.

There are basement de-watering systems that combine a hard plastic wall liner with an interior perimeter drain.

If you can provide independent research citations on the suitability of spray-on rubber coatings to dry out a wet basement I'd be glad to review and cite them.

Generally the place to start at fixing a wet basement is to find and source of water entry; in many if not most cases that source is roof drainage (gutter defects) problems or surface runoff problems.

Note to readers: In his original post Simon included an advertisement for a rubber liquid coating product that he sells.

...

Continue reading at BASEMENT LEAKS, INSPECT FOR - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Key Basement Dry-Out Articles

• BASEMENT DE-WATERING SYSTEMS
• BASEMENT LEAKS, INSPECT FOR
• BASEMENT WATERPROOFING
• CONDENSATION or SWEATING PIPES, TANKS for examples of condensation on surfaces in wet, damp, or humid environments
• CRAWL SPACE DRYOUT
• EFFLORESCENCE SALTS & WHITE DEPOSITS other white stuff on building surfaces
• FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
• FOUNDATION WATERPROOFING
• FOUNDATION WATERPROOFING: CRACK SEALANTS
• FOUNDATION WATERPROOFING SEALANTS
• GEOTEXTILES & DRAINAGE MATS
• GRADING, DRAINAGE & SITE WORK
• PLUMBING LEAK DETECTION & SHUTOFF DEVICES
• WATER BARRIERS, EXTERIOR BUILDING
• WATER ENTRY FROM BURIED TANKS
• WET BASEMENT PREVENTION - key suggestions
• WET, DEFINITION OF
• WATER ENTRY in BUILDINGS - home

Suggested citation for this web page

WET BUILDING DIAGNOSTIC FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING LEAKS & WATER ENTRY

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