White patches , could it be from urine

karen310

Hi , I have 2 dogs aged 12 and 15 yrs (we think , both rescues so only approx) . Last weekend I cleaned my patio area , and since then have noticed white patches appearing on the paving slabs, I have scrubbed them , but they are not really going and I havent had them before.

I am beginning to think that it could be one of the dogs urine , it is definitley an area where one of them wees , and I think it is probably the elder one as she is female , the other is male so cocks his leg !

I am obviously going to get her to the vets , but am going to test her next puddle with a urine test dip stick. Anyone had anything similar , I assume it could be a urine inf or a build up of calcium or maybe not even from the dogs at all !
Any clues anyone ?

Penny_Watcher

No idea about what b*tch urine does to paving slabs, but I do know it can cause the lawn to have 'burnt' patches.

alleycat`

normally white patches appearing on brick work or slabs is from salt leaching out of mortar and they drying (but only if it is relatively new).
Are the slabs new(ish)?

karen310

alleycat` wrote: »

normally white patches appearing on brick work or slabs is from salt leaching out of mortar and they drying (but only if it is relatively new).
Are the slabs new(ish)?

No , the slabs have been down for about 15 years or more and there has never been any white patches before and the dogs have always weed on them. The white definitley seems to be where she has been and a few other areas (where she may do tiny wees ).

A trip to the vets is best I think.
Thanks anyway

devils_vixen

Following on from the post by Penny Watcher, does anyone know how to restore the grass on the lawn from the "burnt" patches?
My grass is a mess and the recent cold snap hasn't helped - there is one bit inparticular and this is the bit that is urinated on frequently by the dog. I have thought about a pee post - are they effective?
Any advice?
Thanks

Misstress

karen310 wrote: »

Hi , I have 2 dogs aged 12 and 15 yrs (we think , both rescues so only approx) . Last weekend I cleaned my patio area , and since then have noticed white patches appearing on the paving slabs, I have scrubbed them , but they are not really going and I havent had them before.

I am beginning to think that it could be one of the dogs urine , it is definitley an area where one of them wees , and I think it is probably the elder one as she is female , the other is male so cocks his leg !

I am obviously going to get her to the vets , but am going to test her next puddle with a urine test dip stick. Anyone had anything similar , I assume it could be a urine inf or a build up of calcium or maybe not even from the dogs at all !
Any clues anyone ?

What did you use to clean your patio slabs with. My monies on that causing the white patches.
I'd try pouring a cup of water where the dogs dont wee and then see if a white patch appears when it dries out.

karen310

Misstress wrote: »

What did you use to clean your patio slabs with. My monies on that causing the white patches.
I'd try pouring a cup of water where the dogs dont wee and then see if a white patch appears when it dries out.

No it only seems to be where she has weed , but not all the places she wees. The rest of the slabs have been wet since I cleaned them.
Bit of a mystery really.
I cleaned the area with something called Algon , to remove algae and greenness ! But surely it would happen all over if it was that.

Misstress

I was pretty sure it was something to do with the washing of the area.
I googled and i think its prob the fact that you got it very wet and it is bringing the calcium up to the surface.

Efflorescence is a powdery deposit, usually white in color, that appears on the slab surface.

Efflorescence occurs when water in the concrete transports minerals up through the porous slab, leaving a mineral deposit on the slab surface. Efflorescence can cause paint and stucco to blister. The white spots created by efflorescence can create an unattractive appearance, resulting in dissatisfied homeowners. Homeowners may mistake the white spots for mold and call the service department complaining of mold growth on the slab.
Concrete naturally contains compounds of sodium, potassium, calcium, magnesium, and aluminum. Water in the slab dissolves these compounds, creating a salt solution inside the slab. Through capillary action, this solution rises to the surface of the slab, where it evaporates. As the moisture evaporates, the minerals precipitate out onto the surface and leave stains on the slab. The majority of efflorescence found on concrete is calcium carbonate.

Efflorescence during the curing process

Efflorescence can occur while the slab is curing. The slab cures through a chemical reaction between the water and cement. During this chemical reaction, a compound called calcium hydroxide is released. As the slab cures, the calcium hydroxide moves up, along with water, to the surface. Then, as the water evaporates on the surface, the calcium hydroxide is released and instantly reacts with carbon dioxide in the air to form calcium carbonate, which stains the slab surface.

Efflorescence after the curing process

Efflorescence more often takes place once the slab has cured. If the slab wicks up groundwater, the water can move upward through the porous slab, bringing calcium hydroxide with it. When the calcium hydroxide reaches the slab surface, it reacts with carbon dioxide in the air to form calcium carbonate, which stains the slab surface.

jojones55

try putting some brick acid on it
it is not Efflorescence after 15 years.
it will be minerals from the urine reacting with those in the flags.

amy104

I don't have a dog so sorry if this is a bit irrelevant but I have several bunnies and their urine often leaves white stains on the patio. In bunnies its because their excess calcium is excreted in the urine. I'm pretty sure that this is quite unique to bunnies so its probably unlikely the stains are caused by the same thing but if you do think the marks are calcium related the most effective thing I've found which removes them is white vinegar. If its really bad sprinkle with bicarbonate of soda then white vinegar.