I spoke to a floor specialist (that she used) and he said that was due to excessive moisture. 

Maintenance / SafetyAdd carbon monoxide and smoke detectors to 1stand 2nd floor (42) Remove old detectorsInstall gutter downspouts to prevent moisture intrusion (126) Reinstall vapor barrier in crawl space (127) Replace insulation within wall by the bathtub (106)§ To be discussed when wall is openedPine PanelingInstall 1x6 T&G Pine Paneling Everywhere that vertical paneling is currently installed.

There's no obvious signs of moisture/leaks and I've run an ozone generator 3 times at 2 hours each straight into the return vent.

During the inspection process, no red flags were raised for moisture, etc.  

Exterior Decking:Exterior Decking damaged unsafe to use with advanced wood decayExterior Window and Door Framing:Active moisture staining rot and termite damagestone foundation:significant pargement and mortar deterioration needs stone repointing and parged to avoid potential stone shiftingEnvironmental concerns:Basement lot of mold Mold TestsConfirmed cladpsporium and hyphase and pencillium type of modls in basement at unusual levelPest TestsVisible evidence of wood destroying insects and dea insects and termite related damage noticed.

Check your foundation and make repairs- parging isn't that hard to do, and follow it up with a good water proofing paint for the walls and floors.I'd look into the moisture monitors that link up to wifi and have an alert sent to your phone.

I like the moisture cover for the key hole, for our weather.Don't remember exactly the prices.Chain is about $20 per foot.Lock is about $25​Three pictures above is our Cantilever gate.

I close in a Friday on a house with a leaking three layer, moisture forming on the woodwork and mold starting.

If the insulation is wet, it should be replaced so the substrate does not deteriorate from the moisture, compounding the problem.Once you've determined what is causing the ponding and address it; your next step would be to pressure wash the roof area to remove any coating no longer adhered to the roof system.

However, new metal roofing would be more cost effective, but up here we tend to get moisture/humidity build up under the metal sheets & purlins if we do not have an adequate slope.