What is this behind my Sheetrock?

[mark price]

Can anyone tell me what this yellow substance is behind my basement sheet rock beneath the stairs , as well as the vein like strands in the second photo?

 

[Snoonyb]

Welcome.
I do not see any yellow or any streaks.
An expanded panorama and description of the area would be of assistance.

 

[mark price]

Thanks.

The yellow substance is under the the pipe (below is a clear image that appeared on the other side of the stair) and the strands are next to the rock in the second photo (will try to provide clearer images this evening).

 

[havasu]

Mold?

 

[bud16415]

Looks like mold to me also. We have a field stone basement and I get stuff like that. Try spraying some Clorox on a spot and see what happens.

 

[stuart45]

Hard to be sure from a small photo, but dry rot can look similar and can travel across masonry.
https://www.google.co.uk/search?q=d...AhWBJMAKHTOnAwgQ9QEIPTAJ#imgrc=kLNM2vlZLREJIM:

 

[tuffy]

After looking at Stuart45's photo's I vote for dry rot.Had the yellow and the veining.So I guess spray it with some bleach and if it goes away I was wrong wont be the first time and wont be the last.

 

[nealtw]

B

After looking at Stuart45's photo's I vote for dry rot.Had the yellow and the veining.So I guess spray it with some bleach and if it goes away I was wrong wont be the first time and wont be the last.

Bleach is a great disinfectant for hard surfaces like counter tops, there are products for killing mold and rot and it is not bleach on a pores surface.

 

[slownsteady]

Bleach loses it's effectiveness at the surface, but in this case it should be a good test to see if the surface mold responds. It won't solve the problem but it will help determine the problem. You may find the best solution is to remove/replace the sheetrock/drywall.

 

[nealtw]

Thanks.

The yellow substance is under the the pipe (below is a clear image that appeared on the other side of the stair) and the strands are next to the rock in the second photo (will try to provide clearer images this evening).

View attachment 20691

It is any number of things you would not expect to grow on concrete but they all will feed on the dust and moisture on the concrete.
So where is the moisture coming from if it is coming thru the wall, should be stopped before replacing drywall. If it is just warm air moist air with water condensing against the concrete you need insulation and vapour barrier between that room and the concrete.

 

[tuffy]

Told you I would be wrong again (didn't think it would be this quick tho)

B

Bleach is a great disinfectant for hard surfaces like counter tops, there are products for killing mold and rot and it is not bleach on a pores surface.

 

[nealtw]

Told you I would be wrong again (didn't think it would be this quick tho)

You are not alone with that one, you can find bleach suggested all over the interweb.