(781) 793-0700

Is Sealing Exterior Stone in New England a Good Idea?

Jul 12, 2012

Home 9 Commercial 9 Is Sealing Exterior Stone in New England a Good Idea?


Lately we have been getting a lot of requests to seal exterior stone.  Often its tough to give building management and home owners a simple answer other than, “it’s not a good idea.”

Interior stonework finishing

Natural stone in an indoor application is not subject to the same elements as outside. Stone is polished and finished in a completely different manner. In addition, it is usually installed over a subfloor that is going to stay dry.


What happens when exterior natural stone is sealed?

Exterior stone is often installed over a surface that will be exposed to water. If there is water underneath the stone, and the stone is not sealed, ultimately the water will find a way out allowing the stone to dry. If the surface of the exterior stone is sealed, the water will get trapped and can cause an effect called picture framing.  In addition, a situation called efflorescence can also occur.  This occurs when salts and other minerals present in

Example of picture framing or window paning on stone.

various stones are exposed to water. During the evaporation process, these minerals seep out of the stone and appear on the surface as white powder, haze or in some cases, a hard white crust.  Road salt, lawn products for example can cause this issue with exterior installations.


Should I use an Impregnating Hydrophobic Sealer?

Some people recommend using an impregnating hydrophobic sealer.   This is a sealer which repels water and will penetrate deeply enough into the material to keep water and dissolved salts well away from the surface. However, in climates where freezing is a concern, such a sealer may lead to damage from freeze/thaw cycles.

If you are looking to improve the look of exterior stone, we offer excellent exterior stonework cleaning services, call 781-793-0700 for a quote or get an estimate online.


Get your project quoted today

Related posts

Stone Restoration in Harwich, MA

Over the last few years we've photographed 8 projects in Harwich alone. 8! We love our Cape &...

What is Etching on Natural Stone?

Have you got a stain, dull spot or damage on your marble, granite or other natural stone that just...

Can I save my stone countertops?

Natural stone surfaces like marble, limestone, travertine, and soapstone can be honed and polished...

Providence, RI Marble Rotunda Repaired, Polished & Sealed

We recently completed a multiple day stone restoration and renovation project at One Citizens Bank...

Oh Yeah, We Kid-Proofed 31 Middle School Bathrooms

Not every project we do is transforming something old and worn, into something sparkling and new....

Marble Protection: Products that Prevent Etching and Staining

Check out our latest video, courtesy of our video friends at Boston Design Guide, about how we...

Worcester home renovation reveals hidden slate floor

One of the best parts of our job is when a client discovers a stone floor hidden under another...

10th Anniversary of Our 1st Blog Post! Marble Floor Restoration at the Boston Public Library

We can't believe it. It's been 10 years since our first blog post. Since then we've written...

Sudbury, MA Rojo Alicante Vanity Refinished & Restored

Sudbury, MA Rojo Alicante Vanity Refinished & Restored Here is great example of a Rojo...

The Stone Restoration Process in 6 Steps

When we visit events, home shows and conferences, we inevitably meet people who have never heard...