Star Bolts...They Aren't Just Decoration!

Home Inspector with Precision Home Inspection

You’ve probably seen these cool metal stars on old brick houses and thought they were just a quaint decoration.  The truth is that they are often much more than that.

Bulging or bowing in brick walls is common throughout the Philadelphia region, especially on 3 story rowhomes.  Star bolts are one less-expensive way to avoid completely rebuilding the wall.

Our problem starts in the mortar used to hold the bricks together.

Unlike more modern mortar (Portland cement mixtures), the lime mortar that was used pre-1920 (or so) is subject to dissolving when contacted by moisture or water, weakening the mortar and losing both compressive strength and bond strength. Foundation subsidence may also be found to blame.

Star bolts can be used to effectively re-secure loose or bowing wall back to the original state.   These metal stars are often seen on historic homes throughout the area, and are functional, not decorative (although they are attractive and interesting features).

Through the use of a grid work of 2 x 8 planks, backed by 4 x 4 posts, cables, and anchors, bulges of up to 3 inches can be reduced to less than an inch.  Removal of old lime mortar between the inner and outer courses of brick (called “wythes”) is needed to further reduce the gap to plumb.

The 10" diameter "star" plates are installed on ¾” threaded rods, and anchored anywhere from 4 to 8 joists deep in the home (this can require removal of flooring or ceilings).  These rods are fastened in place with washers and nuts and solid bridging (blocking) is installed between the joists. This combines the strength of the joists; essentially producing a 12x10 frame (for 4 joists) to resist brick movement, and allowing the star bolts to secure the exterior bricks in place.

Finally, the bolts may be round, oval, square, diamond, or star shaped. They should be at least 1/4" plate, and at least large enough to hold directly against at least 6 or 8 bricks. Those bricks than apply drag to other bricks around them.   A 20 foot wide house face will usually require 3 bolts per floor.

When properly installed, these bolts prevent the brick facing from sagging toward the street. The framing and flooring create a structural anchor, meaning that the bricks can't move without dragging the framing out into the street.

The cost for replacement of a brick wall can exceed $8000 - Star bolts typically cost approximately $1000 each. So, not only are they functional, they are also fiscally responsible!

Star bolting has been proven for over 100 years (either as original design, or as retrofit) to maintain structural integrity.  While fewer and fewer masons want to install them (they make more replacing the wall), they are a great solution to a common problem.

Comments (53)

Paula Hathaway, REALTOR, LBA
Douglas Elliman Real Estate - Southampton, NY
...A Local Expert in all The Hamptons

What a terrific post---I have seen these in buildings in New York and other places like Boston and often wondered what ever possessed the owners to decorate their houses like that--now I see, and I like them too.! It is Form following function as steven Graham says!

Feb 08, 2011 04:31 PM
Bill Pohl
Tetra Homes, Inc. - Loveland, OH

Thanks for the information. It is something that I didn't know but certainly makes sense.

Feb 08, 2011 04:42 PM
Chris Eckert Real EstateTeam
Keller Williams Realty - San Mateo, CA
Selling the Mid-Peninsula Realtor
Interesting post. I forgot how many unreinforced masonry buildings we have on the San Francisco Peninsula
Feb 08, 2011 04:42 PM
Brin Realty Associates Team At Bean Group
Bean Group | Brin Realty Associates - Amherst, NH
Amherst NH homes and Southern NH real estate

I learned something new early this morning...thanks I didn't know that was their purpose!  thanks.

Feb 08, 2011 09:20 PM
A1 Certified Home Inspections
Lake City, FL

I never even gave them a second thought. Now I know. I wonder why this was never mentioned in my Home Inspection classes?

Feb 08, 2011 11:49 PM
Michael Setunsky
Woodbridge, VA
Your Commercial Real Estate Link to Northern VA

Joseph, I would have guessed they were there for decorative purposes. Learned something new today. Thanks.

Feb 09, 2011 01:11 AM
Ilyce Glink
Think Glink Media - Chicago, IL
Best-selling author, award-winning TV/radio host.

Wow, that is really interesting. We have a lot of brick here in the Midwest as well.

Feb 09, 2011 03:59 AM
Bob Zorechak - ABR, GRI, e-PRO
Keller Williams Realty Metropolitan - Morristown, NJ
Sells Homes in Morris/Somerset/Hunterdon Cos., NJ

I've seen these in NJ and southern New England.  Never realized they were used for anything else beyond decoration.  Now I know better.  Thanks.

Feb 09, 2011 04:12 AM
Barbara Altieri
Better Homes and Gardens RE Shore and Country Properties - Shelton, CT
REALTOR-Fairfield County CT Homes/Condos For Sale

I never knew this.  How interesting. $1,000 instead of $8,000?  I'll take the former instead of the latter!

Feb 09, 2011 06:23 AM
Team Honeycutt
Allen Tate - Concord, NC

Well I just learned something new today!  I always thought they were decorative.

Feb 09, 2011 07:50 AM
Home Repair or Remodel in Arlington TX

Good info.  I didn't know what those were.

Feb 09, 2011 08:14 AM
Peg Barcelo
Fluff My House! Home Staging Inc. 250.486.6369 - Summerland, BC
The FlufftasticStager from Summerland, BC

That's really cool! I live in Edmonton, Alberta, where there can be extreme temperature fluctuations up to 45 degrees Celsius! Everything is affected by that, so I will be keeping an eye out, but I'm certain we don't have as much brick up here.

Thanx for the lesson, I love learning new things!

Feb 09, 2011 10:42 AM
Nick Vandekar, 610-203-4543
Long & Foster Real Estate Inc 610-225-7400 - Devon, PA
Tredyffrin Easttown Realtor, Philly Main Line

Interesting, how old world efficiency works even today to hold things together.

Feb 10, 2011 01:42 AM
Joyce Godwin, Realtor, CRS
RE/MAX Elite Properties; Serving Cypress, Spring, Tomball, NW Houston - Houston, TX
RE/MAX Elite Properties

Joseph, I haven't noticed those in our area.  I am going to have to take notice and see if they use them here also.  I hope so.  They are pretty.

Feb 21, 2011 11:18 PM
Not a real person
San Diego, CA

I would have thought that there were some Dallas Cowboys fans or someone from Texas living there! J

Mar 13, 2011 02:18 PM
Julie McCarthy

Tearing off siding on my 1850 brick schoolhouse home. Found 3 of these bolts. Beautiful. My home is happy again. Saegertown PA.

May 26, 2016 10:47 PM

Wondering if you know anyone that would still do the restoration w these? Have an 1854 Farmhouse that was compromised by previous owner (spring kitchen only). Would like to find someone to repair it.

Nov 06, 2017 01:16 PM
Patrick Quinn

Quinn Brothers Masonry LLC is sure to install star bolts along with any other masonry restoration repairs

Nov 11, 2017 11:19 PM

I collected several of these in Texas just for the “Lone Star” decorative value.

Jul 09, 2019 06:12 PM
Charlie Wimmer

Very good article I am trying to purchase some in the DC metro area but no one seems to no what I am talking about any help you could provide would be greatly appreciated

Nov 25, 2019 06:12 AM