Stairs on Brownstone Eroding


    The space beneath our steps in our brownstone is filled with a brown dust-like substance from falling sandstone(?) overhead. Does anyone know how to fix this problem (if it is a problem?)

    Thank you!

    11 Replies

    1. you can find a brownstone mason in the Brownstoner Directory. “Brownstone &Facade Repair”

    2. If it is brownstone than need to resurface by cheapawya lose part and resurface with brownstone color cement.We do brownstone renovations.You may get an estimate from us.
      M.Hamid Construction Co

    3. Yeah, I had the brownstone crumbly dust issue. The mason
      (Milad – written up on this site) knocked off the crumbling brownstone material and smoothly cemented over the whole area under the stoop.

    4. the damp atmosphere is deadly. Do you have an air vent at the side of the stoop? Even with a vent it can be damp under there.

    5. This is counter-intuitive, but sometimes when the exterior of a stoop – or brownstone in general – is completely sealed, this dusting – think it’s called “spalling” – can happen.

      Brownstone is naturally porous, and if it’s not able to eliminate moisture by evaporation, it will crumble.

      In a moist, under-the-stoop area, you probably won’t get dustiness completely stopped, but brushing and whitewashing would probably slow down the deterioration. You don’t want to use a sealer meant to provide a waterproof membrane or anything like that – it will cause worse troubles down the line.

      Ventilation is key.

    6. I don’t know about your stoop, but the sparrows find ours delicious. They have pecked a hole completely through the brownstone side into the brick layer. Ahh, the joys of home ownership.

    7. Ours sheds too. I think it’s endemic to the under-the-stoop space. Probably because of the moist “micro climate” there.

    8. agree with arkady, get a mason out to take a look. we had ours redone when we did our facade, painted it with a sealant and guess what…it still flakes. hope your mason does a better job than ours.

    9. I’ve got the same exact issue- and its not brick dust, its exactly as you described it- brownstone dust. It is eroding on the ceiling of the space under the stoop.
      The brownstone material is crumbling off and you can brush it and it dusts off- not in flakes really, but a cloud of dust/sand-like material.

    10. Have someoe do a skim coat of mortar. Isn’t the interior brick? I suspect it’s brick dust, not brownstone dust.