Should You Remove the Paint From Your Brownstone?

This question comes up on almost every painted facade we survey. Owners either hate the look, or they have been told the paint is killing the stone. Both are worth taking seriously, and both need the same first step: finding out what is actually under there.

Why brownstones got painted in the first place

Very few were painted for looks. Brownstone is a soft sandstone that weathers, and by the middle of the last century a lot of facades were already flaking. The cheap answer was to skim the front with a cementitious coating, often called brownstone coating or brownface, and then paint over it to even out the colour.

So on a large number of houses, the paint is not sitting on original stone at all. It is sitting on a repair layer that was applied decades ago, sometimes several layers deep. That matters enormously, because stripping the paint does not reveal a Victorian facade. It reveals whatever was done in 1965.

What paint does to the stone

Sandstone needs to breathe. It absorbs moisture and releases it back out through its surface and through the mortar joints. Most modern paints form a film that slows that down badly.

Water still gets in, from the roof, the parapet, failed joints and driving rain. Now it cannot leave the same way. It moves through the stone until it finds an exit, and when it freezes on the way out it takes the face of the stone with it. That is why painted facades often blister and flake in sheets rather than weathering evenly.

The same principle governs mortar, which is why we insist on soft lime based mixes for repointing. Anything that traps water in the wall eventually damages it.

Signs the paint is causing damage

• Blistering and peeling in sheets, especially on the sunniest or wettest elevation. That is moisture pushing from behind.
• Hollow sounding patches when tapped. The coating has separated from the stone and is holding water in the gap.
• Flakes that come away with stone attached, not just paint. This means the surface of the sandstone is already going.
• Damp inside on the wall facing the street, particularly at parlour and top floor level.
• White staining or salts at the edges of the paint, where the moisture is finding its way out.

How paint should and should not come off

Removal is done chemically and slowly. Poultice strippers are applied, left to work, and taken back with low pressure rinsing, usually in test patches first so the effect on the surface can be judged before the whole facade is committed.

What must never happen is anything abrasive. Sandblasting removes the hardened outer skin of the sandstone along with the paint, and once that skin is gone the stone weathers many times faster. It is banned on landmarked buildings for exactly this reason, and it is a bad idea everywhere else.

What you may find underneath

This is the part worth preparing for. Once the paint is off, a facade can turn out to be any of the following, often all on the same house:

• Sound original stone, which is the best case and does happen, usually on protected elevations.
• Old cementitious coating, hard and grey, which then has to be dealt with as its own problem.
• Patches of previous repair in several colours and textures, which will need refinishing to look like one facade again.
• Spalled stone, where the face has already gone and rebuilding or resurfacing is the only route.

None of these are reasons not to strip. They are reasons to open a test patch and see, before signing up for a full facade and a budget that is really a guess.

When repainting is the better decision

If the stone under the paint has already spalled, or the coating is holding a fragile surface together, taking it all off can leave you with a facade that needs full rebuilding. In that situation the sensible plan is often to keep the surface covered, but to change what is covering it.

A breathable mineral coating lets vapour pass through while still protecting the face. It is not the romantic answer, and it does not give you bare stone, but it stops the freeze and thaw cycle that is doing the damage. Paired with proper waterproofing and restoration, it buys decades.

Frequently asked questions

Thinking about stripping your facade? Start with a survey and a test patch. We will tell you what is under the paint before anyone quotes a full elevation, and if repainting is the better decision we will say so. Call (917) 297-7377 or email contact@brownstonerepairnyc.com.