(773) 588-0800

Bidding Lime Mortar Projects

We work with a wide range of contractors, many of whom are working on lime mortar projects for the first time and have many questions on how to bid and plan the project. If you have read our guide to pointing, curing, and washing lime you should have a good overview of how to work with the material. Our website also features brief video demonstrations.  Here are a few important notes:

  • Lime mortar is installed much drier than most modern mortars and should be the consistency of brown sugar. You should never use grout bags or pointing guns. You should also plan on installing lime mortar using back fillers.
  • Many specifications call for you to install mortar in fine lifts. Unless you’re installing nonhydraulic lime putty (which needs brief exposure to the atmosphere to initiate carbonation) this is unnecessary. Lifts are only necessary when sagging is a concern.
  • Lime mortar requires more attention during curing than cement lime mortars, so you will need to plan ahead in order to keep it protected. Preferably the mortar should be covered with burlap and misted for at least 3-5 days, including weekends. This is especially important if the weather is very hot or windy.
  • Lime mortar should be installed when it is 40 degrees and rising and protected from frost for at least a week. Never use admixtures.
  • You must plan to work neatly because cleaning is not an option after installation.
  • We will be happy to provide referrals if you would like a custom training session.
  • Lime mortar is a specialty product and you should anticipate budgeting at least 2-3 times the cost of conventional Portland cement-lime mortars. Here is a chart of options to help you with your estimate:

NOTE: All products in this chart are unpigmented – Pigmented mortars may accrue additions costs.

bidding mortar chart

Below is a list of data and MSDS sheets from the products in the chart above:

Niagara PHL 3.5 (50lbs)  Datasheet

Niagara PHL 5.0 (50lbs) Datasheet

St. Astier 2.0 (55lbs) Datasheet & MSDS Sheet

St. Astier 3.5 (55lbs) Datasheet & MSDS Sheet

Custom Color & Aggregate Matching

We have matched thousands of mortars and we retain samples from all of our jobs. When we are asked to match a mortar color, we first check our existing formulas for a match. If we have a match that is approved, we do not charge a color matching fee. Color matching and aggregate matching fees are $250/sample for most projects; custom materials or more complicated projects may have a higher fee schedule. You should anticipate a two-week lead time for custom color matching although it may be faster; much of the timing depends on the workload in the laboratory and the difficulty of the match. We do have to allow the samples to cure, so inevitably there is some unavoidable lead time to the process.

In some situations, you may bid on a project that doesn’t specify a certain type of mortar. Instead, you may be asked to simply “match existing” or you may be required to commission testing to establish a compatible replacement. When the type of mortar is not specified but lime mortar is likely the best option, it is very difficult to get apples to apples bids. Low bidders who budget for conventional mortars have an advantage over those who favor lime mortar because typical cement-lime mortars are commodity materials with simpler, more familiar installation and curing procedures. When no mortar type is specified, we suggest submitting two allowances: one for conventional mortar and one for lime mortar. This enables you to demonstrate your price competitiveness while also providing a realistic budget number if lime mortar is the more appropriate material. In too many cases such loose specifications disqualify the bidders who price appropriate materials, only to have the low bidder submit a change order after the job is awarded.

Once we have matched the mortar, we will provide a set of laboratory cured channels for client review and approval. We record and retain all formulas for our projects so that the mortar formula can be recreated at any time.

We offer two options for custom color matched mortar: preblended by the bag (50lbs or supersack with silo system) OR colorpacks that can be added to our preblended PHL and NHL mortars. (Only available with mason sand for standard sized joints.) Colorpacks are best suited for smaller jobs that require fewer than 20 bags.

Pricing for preblended custom mortars is dependent on the bag quantity, aggregate, and pigment load so cost is highly variable. In situations where lime mortar is likely to be the most compatible material, we are happy to provide budget numbers based on comparable projects.

Preblended mortar should be considered when:

  • site limitations prevent onsite mixing
  • the mortar is pigmented and will require consistent, precise blending to achieve the desired appearance
  • locally available sand is not an acceptable match
  • labor costs associated with blending need to be minimized

Anticipating Leadtime

We advise allowing a lead time of 1-2 weeks to produce a custom blended mortar. Lead times can be shorter, but this production time will need to be factored into your work schedule. During the spring/summer peak these estimates may be longer. If we need to do a custom color match plan for an additional 1-2 weeks when the development of a new color formula is required.

Mockup Panels

We always recommend installing a mockup panel that is at least 3’ x 3’ to demonstrate how the mortar will be removed without damaging the masonry units as well as any cleaning procedures, and to establish the agreed-upon joint profile and color of the cured mortar.  This ensures that the standard of workmanship is accepted by all parties before the job starts. You should budget for this work and include it in your bid.

Bidding Jobs when the Mortar Hasn’t Been Determined

In some situations, you may bid on a project that doesn’t specify a certain type of mortar. Instead, you may be asked to simply “match existing” or you may be required to commission testing to establish a compatible replacement. When the type of mortar is not specified but lime mortar is likely the best option, it is very difficult to get apples to apples bids. Low bidders who budget for conventional mortars have an advantage over those who favor lime mortar because typical cement-lime mortars are commodity materials with simpler, more familiar installation and curing procedures. When no mortar type is specified, we suggest submitting two allowances: one for conventional mortar and one for lime mortar. This enables you to demonstrate your price competitiveness while also providing a realistic budget number if lime mortar is the more appropriate material. In too many cases such loose specifications disqualify the bidders who price appropriate materials, only to have the low bidder submit a change order after the job is awarded.

Resources to Support Your Bidding Documents

When bidding projects without clear specifications for lime mortar, it may be helpful to provide independent authoritative resources that help support your proposal and underscore the importance of using lime mortar to the specifier and/or building owner. Here are some of our recommended documents that can be included with your submittals:

Documentation from the National Park Service: The Technical Preservation Services division of the National Park Service develops historic preservation standards and guidance on preserving and rehabilitating historic buildings, administers the Federal Historic Preservation Tax Incentives Program for rehabilitating historic buildings, and sets the Secretary of the Interior’s Standards for the Treatment of Historic Properties. If you are working on a restoration project that is applying for historic tax credits, or that is under the auspices of a historic preservation commission, these standards serve as the guidelines.

In addition to the Standards, TPS provides their Preservation Brief series, and Preservation Brief #2 is an important industry reference: Preservation Brief #2: Repointing Mortar Joints in Historic Buildings

For more information please contact Elisabeth Logman at 773-588-0800 x113 or elogman@hfsmaterials.com.