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Why does condensation collect on the surface of ceramic tile along interior wall?
QUESTION
Why does condensation collect on the surface of my ceramic tile along my interior wall? - Had a ceramic floor installed in our kitchen and dining room. The dining room has an exterior wall facing west, and a cement slab foundation. When the weather turns cold, moisture will bead up on the tile along the baseboard on the wall facing the outside. Not sure how to fix this issue, short of removing the tile. Any information would be appreciated.ANSWER
Answer - If I understand you correctly, the ceramic floor tile in the interior of your home that sits adjacent to your baseboard at an exterior wall has moisture condensation on the tile along the baseboard.The general rule is that if there is moisture vapor present in the atmosphere that it will condensate at its dew point (the temperature below which the water vapor in air condenses into liquid water).
So chances are, that moisture is migrating into your concrete slab from the exterior and the moisture is migrating up to the slab surface at the seal plate and into the tile assembly and evaporating up through the grout joint (assuming your tile is impervious or very dense). When the temperatures start dropping on the tile floor then the air (that has a high relative humidity percentage), coming up at the wall, comes into contact with the cold tile surface and condensation occurs. Since this condensation on the tile surface only occurs at the wall to floor interface, then we assume the atmospheric relatively humidity of the interior home is not high, and it is air traveling up from the perimeter of the house that has the high relatively humidity meaning it contains a lot of moisture.
In terms of what is causing this high moisture air to develop at the wall to floor interface. You probably don't have a vapor retarder membrane installed under your concrete slab or it isn't installed correctly. The vapor retarder is suppose to continue up the side of your footings to prevent any moisture from the outside to migrate through the slab and vaporize into the interior space. Compounding this could be that either your planters adjacent to your home are getting to much moisture from either over watering or roof gutters are dumping water into your planters or your landscape is not properly sloped away from the home.
In terms of how to prevent the high moisture air from developing at the wall to floor interface. You can waterproof the sides of your footings and slab by continuing the vapor retarder up the side of the slabs. You can install a French perimeter drains so water can't reach your slab. You keep your planters from getting excessive moisture.
You could possibly caulk/seal the baseboard opening with an appropriate silicone or urethane sealant to keep the air from flowing through that point, but then it might cause the moisture and vapor to find another spot to migrate to that could condensate and cause even more severe water damage. Best to fix the problem rather than try to fix the symptom. Good Luck.
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The water is not coming from the outside, so a vapor barrier will not help. This water is pure condensation from the warm, moist air inside the house.
The slab along the exterior wall becomes cooler as the outside temperature drops. If the slab is cooler along the wall, the tiles along the wall are cooler than the tiles farther away from the wall. Moisture in the air condenses on the tiles just like it does on the outside of a glass of ice water.
We often say that the glass “sweats,” but this is a misnomer. The water on the outside of the glass comes from the atmosphere, not from the inside of the glass.
The water on the tile floor is condensation that collects on the cold tiles along the exterior wall. You can prevent it by keeping the tiles along the wall as warm as the other tiles in the room. Add better insulation along the lower portion of the exterior wall. Install in-floor electric heating mats under the tiles. Blow warm air along the baseboards with fans.
Your description of the physics of condensation is correct. Condensation from the moisture (relative humidity) in the atmosphere does condensate on the warm side of a material acting as a membrane; meaning the material has a low water vapor permanence rating.
Although it is not normal for condensation to occur on the interior surfaces of tile unless you are in bathroom using the shower.
It is well known and documented that vapor retarders are required under concrete slabs and often we find that they are not present or not installed correctly allowing moisture to migrate from the exterior to the interior through the concrete slab. This is particularly important for floor covering materials as many are negatively affected by moisture.
In the above case the only way to fully understand the source of the moisture is to perform an investigation. Because the condensation is only found on the interior floor adjacent to the exterior wall that suggests that moisture is traveling from the outside. If the relative humidity atmosphere was so high on the interior to cause condensation, then it would occur throughout the house where the tile is installed over a cold concrete slab.
Searching for answers to my flooring in my kitchen the same thing happens to me. The floor is a bitumen dark brown impermiable type that was laid when the house was built in the 1950’s and only occurs when it rains regardless of what time of year it is it happens along the outer two walls as it is an end of terrace. I am at loggerheads with the housing who own the property as it has caused severe mould on these walls. I am desperate for answers.
As stated in the other entries, it is likely a combination of factors. There is no vapor retarder under the slab or it has degraded. And then when it rains it is either the water table rises subjecting the concrete slab to moisture that migrates up through the floor or water is draining towards the house from a higher level and subjecting the concrete slab to moisture. Either case, if that is the problem, the only solution is either put in french drains surrounding perimeter of the house to allow sub-terrain water to drain away, or you can remove the existing floor and install an epoxy vapor barrier and install your tile on top of that. You might have to do both depending on your situation.
I have a house that I built about 2 years ago that has condinsation on a screened in porch with tile flooring. This problem only occurs during the Fall and Winter months. The porch has a block foundation with metal decking and a 4” concrete slab poured in place. It is an unconditioned crawl space under the porch that has foundation vents approximately six feet apart along the foundation. There is a 6 mil poly vapor barrier on the ground that provides about 95% coverage. Condintaion collects on the tile surface and also on the underside of the metal decking. The homeowner uses the porch almost year round with tower type propane heaters. Can you suggest a cause and remedy for this problem?
Condensation develops on surfaces that are colder than the air above it, as long as the air above it has a high degree of humidity. Once the humidity vapor cools to a particular dew point, then condensation occurs.
The tile floor and the space below it is cooler than the air above it. By using a propane heater, it not only heats the air but it introduces moisture raising the humidity in the air. Thus it produces condensation on the tile surface.
The remedy would be either use a dehumidifier to remove the moisture in the air or to heat the floor. There are electric floor warming systems that you can place on the bottom of the substrate.
Just paid 48×48 exterior porcelain on large balcony but it rained and its wet underneath and between joints. Will use epoxy grout, but waiting for the joint area and underneath tiles to dry a little. Any suggestions if i should epoxy grout while joints are a little wet to prevent more moisture from getting in? Or a way to speed up the drying to underneath tile and joints? Really appreciated.
The grout joints need to be dry before installing epoxy grout or you will trap moisture. You can use a heat lamps to help dry it faster.
Thank you.
What if moisture is also underneath porcelain tiles? waiting for summertime and or heat lamps may be the only way to dry and then epoxy grout.
Read the epoxy data sheet installation directions. They will normally indicate if the substrate can be Saturated Surface Dry (SSD) meaning it can be damp, but not wet. If you don’t have a mortar bed beneath the tile and it is bonded directly to the concrete, it won’t take long in warmer weather for it to dry out.
Thank you. I used a wet vac and sucked out 2 gallons of water and then stuffed cotton rugs between the problem areas and took out any leftover water. Will be sunny in the low 60’s the next week so hope it dries more.
Is it a good idea to tape 2” left and right of joint before applyung the epoxy grout? Less mess and easier to clean?
Not sure why you had 2 gallons of water to vacuum out. I assume this is a raised deck and you don’t have an adequate slope on the surface for the water to drain off. If the deck is on the ground and water is coming up through the concrete slab then you have a big problem with hydrostatic water pressure. If it is a raised deck and you don’t have an adequate slope for the water to drain off that is problematic too. The epoxy grout might help keeping the water from going beneath the tile, but you will likely get puddling of water.
With a tile epoxy grout it shouldn’t be necessary to tape on each side of the grout joint.
Thank you. Its a raised deck and yes its barely sloping. In the past ive used a product by an Italian company called Antirain by Diasen, which is a clear sealer that protects from water penetration and needs to be applied every couple of yrs.
Ive used it and it works and can create a little slope as needed.
Thanks again, really appreciate it.
There are 3 or 4 tiles that have 12inch hollow corners. Whats the best way to fill the hollow under the tiles since i have not grouted yet? The joint is 1/4 inch and hoping maybe pushing the grout deeper may do it, but a narrow syringe type in the joint might work better. Any suggestions appreciated. Thank you!
If the grout joints are fully open and there are voids along the side of the tiles then you when you do the epoxy grouting it will flow into those voids. To help it along I would fill the grout joints half way with epoxy and then get a tool to force the epoxy down so it feels those joints. Then immediately fill the rest of the grout joint with the epoxy. If you don’t fill the voids then when you do grout with the epoxy it will flow into those voids slowly and you will get low spots in your epoxy grout.
Thank you! Tried to force some epoxy and some did, but not enough i dont think. So i grouted it and there alot of moisture on deck this morning.
Any epoxy low spots, i can always apply some on top.
We have a tile floor on a thin concrete layer over a well insulated crawl space. During the humid summer moisture condenses on the floor and we now have a sheetrock ceiling above the tile that continually peels paint. I am thinking that our only options are to cool the house (we don’t have air conditioning, but we do have a heat/air
exchanger), close everything up for the morning and dehumidify until the tile gets warm enough, or try to heat the tile with a dehumidifier in the crawl space (which has radiant heat and insulation between the crawl space and the first floor of the house.
We have had many opinions given, but your understanding of this type of problem makes the most sense.
Thanks for your help
Sheetrock is not water resistant. I would replace the sheet rock with a Coated Glass mat Gypsum Panel that meets ASTM C1178 that has a waterproof surface. Or remove the paint on the sheet rock and apply a waterproof membrane over it. You will have to cover the membrane with ceramic tile or a cementitious modified thinset mortar skim coat to prevent the membrane from degrading. Installing a Dehumidifier might help too.
I have a encaustic cement tiles (80-100 years old) laid in the entrance hall of my home. They were cleaned and polished by grinding them down with different grits and looked great when done. About a 1-2 years later the tiles went dark and looked dirty and they feels rough to touch, not smooth anymore, and I have noticed there is often condensation sitting on the tiles at certain times of the year usually in Spring and Fall. Underneath the entrance hall is a cellar/basement which is open to air circulation and the house is often closed up. I think what is happening is the air in the cellar is a different temperature to the entrance hall and therefore condensation forms which then is turns into a type of limescale. Same tiles through rest of the house are fine. The house is in Malta so weather is very humid. My question is, would sealing the tiles after polishing prevent this? My only other option i can think is to lift the tiles, place a moisture barrier or even underfloor heating and re-lay the tiles. Currently there is no membrane…tiles are laid on limestone slabs and dirt as was done 80-100 years ago. Welcome any other comments or ideas.
The original encaustic tiles were clay tiles. The cement based encaustic tiles replicating this ancient look are porous and can be restored by grinding and polishing.
Sounds like your tiles are not bonded to the underlying substrate that is over a basement. One way or the other moisture is collecting under the tiles, which could be through the substrate or from water over the surface that migrates down to the substrate.
The moisture then migrates to the tile surface where it evaporates and precipitating the residual calcium minerals that the moisture collected on the way up to the tile surface.
After you have restored the tiles, you can try use a sealer to try to minimize the moisture transition, but that is treating the symptom of the moisture problem and is only temporary. You will have to re-seal the tiles at least every year if not more often.
The problem is the moisture. To treat the problem is to stop the moisture. Applying a waterproof membrane over the substrate and then installing the tiles over that might work as long as the sand bed between the tile and membrane isn’t too thick.
I am considering putting tile on the wall inside my bathroom on an exterior facing wall but am concerned about condensation in the winter months as I live in a cold climate. Are there any considerations I should make to prevent/minimize condensation outside of what is normal in a bathroom?
From what I have read, the rule of thumb is is to place low-permeability materials/retarders on the wall’s warm side, and higher permeability materials on the cold side.
Depending on your substrate type, you would put an ASTM D266 or D227 Roofing felt membrane over the studs or over the CMU. Or an ASTM C171 Duplex reinforced asphalt pater. or an ASTM C171 or D4397 Polyethylene sheeting with at least a nominal thickness of 4 mil. There are other types depending on the substrate you are installing over that have lower perms.