[MassHistPres] reservoir gatehouse restoration

[Hollister, Susan]

Mr. Shaw:
I applaud your restoration work, however I would absolutely not recommend any sandblasting on this structure (or likely any other historic structure).  Sandblasting can destroy the fired finish on the brick and allow water to penetrate and deteriorate the material.  Even hard stones such as granite can be damaged by sandblasting.  http://www.cr.nps.gov/hps/tps/briefs/brief06.htm

If sandblasting is being considered to clean the structure there are a number of excellent masonry cleaners specifically formulated for historic masonry.  SureKlean Restoration cleaner by ProSoCo is one I have used and most masonry contractors are familiar with this product.  Diedrich Chemical is another.  Even with a product like either of these test patches should always be prepared in an obscure area to monitor dwell times prior to full cleaning.  There are cleaners formulated for specific work - removing paint, cleaning rust, cleaning soft/porous stones like limestones and marbles vs. harder materials, etc.  The selection of a proper product for the appropriate application is key.

Likewise repointing samples to approve cutting, color, and installation of the mortar are critically important.  Major damage can be done by using grinders on horizontal joints if the blade is too thick and the contractor isn't careful.  Vertical joints should only be cut by hand tools. Grinders should only be cutting out the mortar, never the brick. 

Ideally the existing mortar should be tested to determine its constituents so that an appropriate match can be made.  If this isn't possible use a soft mortar (one with a 1:2:6 type formulation [portland cement/lime/sand]) instead.

The National Park Service has an excellent brief on historic masonry that you should probably review before embarking on your project or hiring a mason.  http://www.cr.nps.gov/hps/tps/briefs/brief02.htm  The key is finding a good, experienced mason that has worked on historic buildings.  Ask to see a list of similar projects on historic buildings before you hire someone.

Lastly - there are lots of reservoir gatehouses around that were constructed at a similar time for the MDC system.  I would just drive around and look at their doors to get an idea for a replacement.  I know of one that is visible from Rt. 1 in Saugus, several at the Chestnut Hill Reservoir in Newton, several around Rt. 30/Lake Cochituate in Framingham/Wayland and one down off of Rt. 18 in Achusnet that is part of the New Bedford water supply system.

Good Luck
Susan Hollister

-----Original Message-----
From: masshistpres-bounces at cs.umb.edu
[mailto:masshistpres-bounces at cs.umb.edu]On Behalf Of William Shaw
Sent: Wednesday, May 10, 2006 9:47 AM
To: masshistpres at cs.umb.edu
Cc: MHo12345 at aol.com
Subject: [MassHistPres] reservoir gatehouse restoration


In Hopkinton, we (the Historical Commission) are preparing to restore a 
small, brick gatehouse structure at the WhiteHall Reservoir, c. 1920, to its 
original grandeur (photo attached).

We've approached several contractors about restoration work, but have a few 
unanswered questions - any help from the listserv?

1.  What type of door would have been typical for a public utility building 
of this period?
2.  Would sandblasting represent a threat to the longevity of the exterior 
brick and stonework?
3.  Any other restored reservoir or pump station buildings in Mass that 
might serve as an example?

Thanks!

Bill Shaw.