Last month we had a seminar at Wrightwood-Ashburn Public Library about "Vintage Home Masonry Repair." The seminar was presented by Matthew Wolf, Building Materials Division Manager of Henry Frerk Sons. Henry Frerk Sons have long been a favorite masonry consultant and supplier among our members and are considered experts in their field of historic masonry.
Matthew was generous enough to create a "Masonry Cheat Sheet" handout for the seminar attendees. We want to make sure everyone has access to this valuable information, so we've typed it out below--and you can download and print Matthew's original handout at the bottom of this blog post.
Masonry Cheat Sheet
by Matthew Wolf, Henry Frerk Sons
Selecting a Good Contractor
Can they provide addresses to jobs they performed 10+ years ago?
Can they provide addresses to jobs they performed in the last year?
Can they provide you with a copy of their insurance certificate showing workman's compensation coverage?
Are they willing to create sample mockups on your building (grinding, cleaning, pointing)?
Ask what materials they plan to use on your project and ask them to provide product data sheets.
Ask how they plan to prepare your masonry for cleaning, pointing, etc.
Selecting Proper Mortar
Use a pointing mortar that is weaker than the original mortar.
Use a pointing mortar that is weaker than the surrounding masonry units (i.e. brick, stone, etc.).
Use a pointing mortar that is more vapor permeable than the original mortar.
Use a pointing mortar that is more vapor permeable that the surrounding masonry unit.
Use a sand that is well graded with some fine, lots of medium and some course grains.
The largest grains of sand shall have a diameter roughly 1/3 the width of the mortar point.
Mortar joints shall be removed to at least 2 times the width with a 1/4" minimum depth (Ex. 1/2" wide joint should be cut back 1" deep min.).
Mortar shall not be applied at feather edge thickness. Patchwork must be applied at a minimum of 1/4" deep.
Patch area shall be of regular geometry with straight edges and near right angles (no curves or sharp angles).
Remove as much old mortar from masonry units as possible so mortar obtains direct contact.
Remove all dust and debris from area to ensure sound bonding.
Follow above steps without damaging masonry units.
Pre-wet the wall with copious amounts of water.
Apply mortar in one lift (not in multiple successive layers) using proper sized pointing tools. Grout bags or tuckpointing guns are not recommended.
Tool joints neatly so as not to smear mortar onto units. DO NOT BRUSH WORK!
Slowly cure mortar for at least 3-7 days.
Caulk shall only be bonded on two sides.
Use backer rod to de-bond bottom side of caulk joint.
Use backer rod to set proper depth of caulk joint.
Depth of caulk joint shall be 1/2 the width at the center.
Caulk joint shall have convex tooling so as to provide hourglass shape in section.
Always use caulking primer.
Never caulk on wet surfaces.
Only use caulk on moving joints.
Chemicals and Repellents
Do not clean buildings unless absolutely necessary.
Not all masonry needs to be "sealed" with water repellents.
Create test panels on every type of substrate to ensure product(s) will not damage masonry.
Use the weakest effective cleaning solution on your masonry. STRONGER IS NOT BETTER!
Never apply paints, sealers or any other film forming coating to masonry. Only deep penetrating water repellents or stains shall be used.
Masonry Restoration Bill of Rights
by Larry Jones
Article 1: "Respect all that is left of me, sacred as it is, my historic fabric."
Article 2: "Clean me not, unless it serves to halt my further deterioration."
Article 3: "But if you must clean me first, just plain water please" (or the weakest effective cleaner).
Article 4: "If I am clean but still look old, leave me be; graceful aging it is called."
Article 5: "Whatever you do, please don't boil me in acid or scour me with sand."
Article 6: "Know that a good state of repair is, in itself, good preservation."
Article 7: "Know what is wrong with me before you plan how to fix me."
Article 8: "Repair me only where I need it, and with materials just like me."
Article 9: "If I am leaking water, find out where and fix just that."
Article 10: "Please no cure-all treatments to cover me up or clog my pores."
[Below added September 27, 2017]
Special offer from Henry Frerk Sons for our members!
Henry Frerk Sons' field consultant, Matthew Wolf, is available to do on-site consultation, written scopes of work, DIY training, and more!
On-site Consultation - Matt will visit any job in the Chicagoland area and discuss the issues he sees with the building owner for a flat fee of $150.
Written Scope of Work - Matt will prepare an in-depth written scope of work discussing all masonry related issues, how to properly correct these issues, what correct materials should be used and what installation methods are necessary. A written scope of work will also include pictures of the issues found, profession drawings showing how these issues should be corrected and all product data sheets. Scopes of work can be extremely helpful during the bidding process so all contractors are bidding the same scope of work and each bid is comparable. The building owner can refer back to the written scope of work to ensure the contractors are correcting the issues properly and with the correct materials.
Do-it-Yourself Training - In the past building owners wanted to save money by performing some of the work themselves. Matt is available for hands on training either in the field or in our training facility to show building owners how to properly make their own masonry repairs.
Matt Wolf is the Vice President for Henry Frerk Sons. Henry Frerk sons has been in Chicago since 1888 (that’s longer than our bungalows have been around!) and is a supplier of building materials, concrete, and restoration and preservation materials. The Frerk restoration team is an acknowledged group of masonry nerds who really really love lime mortar, and always go the extra mile in not only educating members of the Chicago Bungalow Association, but also equipping them to be able to navigate all of the “bad” contractors out there who will try and take advantage.
www.hfsmaterials.com | 773-588-0800 | 3135 W. Belmont | Chicago IL