Electrical panel knockout rust, house in Florida (C) CBBuilding Water Entry & Wet Basement FAQs
Diagnostic Questions & Answers about building water entry, high moisture, condensation, leaks, & wet basements or crawl spaces

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

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.

Green links show where you are. © Copyright 2017, All Rights Reserved.

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

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

White corrosive deposits on galvanized hurricane ties in a Florida home (C) CB Recessed light wiring rust in a Florida Home (C) InspectApedia CB

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.

White paint overspray and rust in a Florida Electrical panel box (C) CB

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 is a link to 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: 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:

Rust on recessed light armored cable "whips" in a Florida attic (C) CB

  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.
  2. 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]

Electrical panel knockout rust, house in Florida (C) CB Rusty electrical panel face knockouts (C) InspectApedia CB

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

Rust stains on a circuit breaker mean it's not safe to continue in use (C) CB

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.

Water marks on joist or truss upper edge (C) CB

  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.

White spray paint overspay into electrical panel ( C) CB Paint on circuit breakers (C) CB


  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. 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:

Question: how to diagnose the cause of ceramic tile failure over a wet floor or crawl area

Ceramic tiles lifting due to wet subfloor struture (C) InspectAPedia

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 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 .


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: liquid rubber for waterproofing basement walls?

(Mar 19, 2016) (mod) said: [We include Simon's comment after deleting his sneak-attack at inserting an advertisement for his company and product - Ed.]

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: 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.

Key Basement Dry-Out Articles


Continue reading at BASEMENT LEAKS, INSPECT FOR or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see CONDENSATION or SWEATING PIPES, TANKS for examples of condensation on surfaces in wet, damp, or humid environments

Or see WET BASEMENT PREVENTION - how to fix the problem

Or see EFFLORESCENCE SALTS & WHITE DEPOSITS other white stuff on building surfaces

and FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP where we include additional photos of basement water entry.

Suggested citation for this web page

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


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Questions & answers or comments about how to determine the extent and history of basement water leakage at a building.

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman