Homeowner FAQs

You should use PHL 5.0 with your choice of sand or a preblended PHL 5.0 that already has sand mixed into it.

 

If you choose your own sand paired with non-preblended PHL 5.0 make sure it is well-graded with some fine, course, and mid-sized grains. The largest grain of sand should be 1/3 the width of the joint you are filling in order to avoid shrinkage cracks.

If it’s a white powdery buildup it’s most likely efflorescence. Efflorescence occurs when masonry is saturated with water, bringing the soluble salts in the masonry units to the surface. Efflorescence is oftentimes a symptom of a larger issue such as water intrusion. It should be addressed quickly as efflorescence can make the surface of the masonry unit friable, leading to spalling.

 

While many building owners are concerned because they don’t like the way efflorescence looks they should first focus on the water infiltration that’s causing it. The first step is to figure out the source of the water that’s soaking your masonry and deal with it. Common causes are overflowing gutters and clogged downspouts, improper flashing, sprinklers, and a lack of drainage around the building. Using hard, impermeable mortars, sealers, and repair materials can also trap moisture in the wall system eventually leading to efflorescence rising to the surface. (This is illustrated in the photo above where modern mortar is applied over the original, softer mortar, effectively forcing the water out through the relatively soft masonry units.)  If you have inappropriate repairs, these need to be removed and replaced with more sympathetic materials.

 

Efflorescence will usually diminish and eventually disappear once the problem is addressed but if it doesn’t Ef-fortless by Eaco chem will remove remaining deposits. As always, carefully follow instructions and always do a mockup in an inconspicuous area.

Grind or chisel out mortar joints to a depth of 2-2.5 times the width of the joint or deeper until sound original mortar is located. Saturating the wall can help with mortar removal.

 

The minimum depth of thin joints is 3/4″.

 

Remove all mortar fins left by the grinder from the top and bottom bricks so pointing mortar obtains a direct bond to the brick.

 

Remove all dust and debris from joints to ensure sound bonding.

 

Perform the above steps without damaging the masonry units or building. If you haven’t done this kind of work practice on an inconspicuous area of your neighbor’s house. (Just kidding! But do practice on an inconspicuous spot.)

You do not need to remove all of your mortar to make repairs if only some is damaged. If majority of the joints are intact and the mortar is sound, you can match the salvageable pieces and spot repoint the rest. HFS can custom match the preexisting mortar or provide a fast track match.

 

To learn more about this process please visit the “Guide for Homeowners” page.

A mock-up is a small, inconspicuous area (usually 3’x3′) where repointing, coating, etc. are done as they would be for the entire building. Mock-ups allow the new masonry to be examined for performance and aesthetic continuity prior to installing materials on the entire building. Mock-ups are also useful when deciding between different colors or masonry materials.

 

HFS does not install mock-ups. If you would like a mock-up done before the project is begun you should speak to your contractor. However, we do provide sample-sized amounts of materials that can be used to create mock-ups.

It depends. The most commonly specified test is ASTM C1324 “Analysis of Hardened Masonry Mortar” which is a comprehensive test of historic masonry mortar that is generally specified by architects and engineers as part of a restoration program. ASTM C1324 includes acid digestion, thin section analysis, and x-ray diffraction, and it calculates the cement to hydrated lime ratios as well as sand to cementitious ratios. The lab test results include a written, photo-documented report with limited interpretation which we supplement with our analysis and reference to the ASTM C1324 test data for modern restoration materials.

 

Testing can be very valuable for restoration professionals but when building owners approach us about testing we generally advise against it unless there is an underlying issue that can’t be resolved with proper building maintenance and sound restoration practices.  In the vast majority of cases, we can recommend historically appropriate restoration materials without incurring the cost or waiting time of laboratory testing. In situations where there are more complicated material failures we typically refer building owners to a qualified independent historic masonry consultant or restoration architect who can work on a comprehensive solution that might involve strategic testing of mortar and masonry units.

For a more complete discussion of mortar testing we recommend the following technical articles:

• Mortar Analysis Part 1: Mortar-Making Materials | Lorraine Schnabel / Practice Points
• Mortar Analysis Part 2: Analytical Methods | Lorraine Schnabel / Practice Points
• Mortar Analysis Part 3: Buying the Right Services | Lorraine Schnabel / Practice Points

Mortar analysis is somewhat expensive and may not be necessary for your project.  Thin section microscopical work costs will determine visually what types of materials are present in your mortar (ie. Portland cement, lime, pigment, fibers, etc) but it will not provide any information regarding mix proportions of these ingredients.  For this information, ASTM C-1324 chemical and petrographical analysis is required. If you provide us with a mortar sample we can assist with this binder recommendation process.

Yes, we sell bricks in our yard. Enter through Albany St. and our yard staff will be happy to assist you in getting what you need.

Generally, if your home was built before or around 1930 and contains softer masonry units that require more breathability and vapor permeability. For these,  you should consider using an NHL (Natural Hydraulic Lime) or PHL (Pozzolanic Hydraulic Lime) mortar.

NHL is ideal for interior stone foundations. However, it has a longer, more delicate curing cycle and takes longer to achieve strength.

 

PHL works well on any common brick homes and most exterior masonry. It is easier to cure and achieves strength quicker than NHL. If you are doing repairs yourself, this is usually a better option because it is easier to install and cure.

Although HFS supplies all of the appropriate materials required to rebuild or repair your chimney, we do not do actual contracting work.

 

 

It is not uncommon for chimneys to fall into disrepair.  Chimneys are considered “cold walls” because they are subject to the harsh elements of heat, cold, frost and moisture on all sides.  Do not be surprised of the contractor suggests removing and rebuilding your chimney.  Often chimneys need to be taken down to just below the roof rafters and rebuilt if the mortar between the bricks has rotted away and/or the clay flue liners within are deteriorated.  The extend of the damage can only be determined upon a close up inspection.  Have your contractor take many pictures to show you the disrepair so you can make an educated decision as to the extent of the repair.

 

 

Proper re-pointing mortars for chimneys are a type “O” cement/lime mortar or a PHL (pozzolain hydraulic lime) mortar.  If rebuilding the chimney is necessary then we recommend re-building with a type “O” cement/lime mortar.  Our historic materials lab can assist you in preparing a custom matching mortar so that your repairs blend in with the rest of the existing masonry.

 

 

When you are making your repairs, pay close attention to how the top of the chimney is detailed as this is the point where water, snow and ice buildup.  If allowed to enter the chimney system it will cause damage again.  We recommend pouring new concrete chimney caps in place.  Have your contractor reinforce the newly poured concrete cap with stainless steel threaded rods.  The concrete cap should have a slight pitch so that water washes away from the flue liner.  The concrete cap should have an overhang on all sides of about 1”.  Ideally, a small ¼” wide channel should be formed into the underside of the overhang about ½” away from the edge of the cap to provide for a drip break.  Your clay flue liner should extend beyond the finished surface of your poured concrete cap by at least 8” and a metal chimney hood should be installed overtop.  All of the items mentioned herein are in stock at our yard.

HFS does not recommend applying any type of waterproof “coating” to the interior or exterior of your masonry wall.  This is especially concerning for masonry walls that are below grade.  Masonry is like a sponge and it will absorb moisture readily.  There is nothing you can or should do about this absorption process; however, you want to pay attention to how the moisture that is absorbed into the masonry wall evacuates.  If moisture becomes entrapped in the wall system it will cause deterioration from within.  Moisture will pull through to whichever side of the wall is drier and warmer.  In the case of basements, moisture is absorbed from the ground and, through capillary action, migrates through the wall to the inside of your basement.

 

 

If you apply a waterproof coating to an interior surface it will entrap moisture and the wall will be unable to dry out.  This moisture will begin to break down the mineral salts within your brick and mortar as the wall becomes more saturated.  When the moisture eventually dries out, the water soluble salts will re-crystalize in the form of efflorescence (the white powdery stuff).  Typically this efflorescence is deposited on the surface of masonry walls as the moisture wicks through the wall and dries at the surface.  Because the coating now inhibits that surface drying process, the efflorescence crystals will form just beneath the surface (subflorescence).  When these little microscopic crystals form within the pores or fissures of your mortar and brick, they exert outward pressure causing your brick and mortar to spall away from the wall.

 

 

If you have already coated the interior of your masonry foundation, it is not quite a helpless case.  The two sides of a foundation wall are referred to as a positive side and negative side.  The positive side of a wall is where moisture typically enters the wall system.  The negative side of the wall is where the moisture typically evacuates the wall assembly.  In this case, the positive side of the foundation is the exterior side and the interior side that was coated is the negative side.  There are two things you can do to correct this problem.

 

 

Option #1

Strip the coating from the interior walls but this is a messy process and it will not stop the moisture from entering the wall from the positive side.

Option #2

Dig out the foundation and apply a waterproof membrane and drainage mat along the exterior side of your foundation walls.  At the base of the footing dig a trench, fill it with ¾’ stone and install perforated PVC seepage pipe running to your closest catch basin.  When you backfill against the foundation, the drainage mat will act as a primary waterproof membrane which will also direct water down your wall and to the seepage pipe which will direct it away from your foundation. The waterproof membrane applied directly to the foundation wall will act as a secondary barrier to “waterproofing” your foundation so no moisture can ever penetrate your wall assembly again.  If you follow this option, you should be able to leave the interior foundation coating in place because there will be significantly less moisture passing through your wall now.  This exterior waterproofing method will also cure most of your rising damp issues which are occurring above grade.

Use polyurethane caulking materials.

 

Caulk shall only be bonded on two sides.

 

Use a backer rod to debond the bottom side of the caulk joint.

 

Use a backer rod to set the proper depth of the caulk joint.

 

The depth of the caulk joint should be 1/2 the width at the center.

 

The caulk joint should have convex tooling so as to provide an hourglass shape in the section.

 

Always use a caulking primer.

 

Never caulk on wet surfaces.

Type 1 – Good for general use.

 

Type II – Incorporates moderate sulfate resistance.

 

Type III – Attains high early strength.

 

Type IV – Has a low heat of hydration.

 

Type V – Incorporates high sulfate resistance.

No, and this is by design. We partner with a qualified independent testing lab to perform mortar and concrete testing and we interpret their test reports to make our recommendations. This approach ensures that the testing is performed by highly trained and skilled scientists and their findings aren’t biased toward any particular restoration product.

• Most concrete is simply stained by general atmospheric dirt. Use a mild masonry detergent (Prosoco’s 2010 All Surface Cleaner) mixed with warm water and aggressive scrubbing to remove general soiling.
• Dark blotchy stains are typically due to biological lichen growth.  Use a proper masonry-grade biological cleaner only (Prosoco Revive).
• Use the weakest effective cleaning solution on your concrete. STRONGER IS NOT BETTER!
• Create test panels on every type of substrate to ensure the product(s) will not stain or damage concrete.
• Never apply paints, sealers, or any other film-forming coating to concrete. Only deep penetrating water repellants shall be applied (Prosoco’s Saltguard).

For more information and tips visit the Cleaning tab under Step 2 of our “Guide for Homeowners” page.

Concrete is inherently very strong in compression but very brittle in tension.  Imagine your concrete foundation was a pane of glass and you backfilled one side of that glass with 5 feet of soil and then added rainwater.  As you can imagine that glass pain would bend inward or possibly even break.  It’s the same with concrete; there is a lot of weight from the soil pushing inward with nothing inside the basement holding the wall back.

All concrete foundations will crack no matter what you do.  In many cases, companies described as foundation crack specialists will tell you that you need to fill those cracks to stop the water.  Typically, the epoxies or urethanes used to inject and fill those cracks are several thousand PSI stronger than the concrete foundation itself.  Your foundation concrete is most likely 3,000-4,000 psi concrete.  What will most likely happen is they will do too good of a job fixing those cracks with too strong of a material and when the brittle concrete foundation wants to move again (and it will) another crack will form.

Sometimes companies specializing in basement seepage will tell you they can install a drainage mat over the inside of the foundation and dig a trench at the base of the interior wall so when water comes into the basement it will flow into the trench and out to your ejector pit.  This almost always prevents you from ever stepping into a puddle in your basement but it still allows moisture and all of its deleterious effects to penetrate your 110-year-old foundation.  So, our preferred method is to stop the water at the source which is from the positive side of the wall.  The following suggestions should be applied to your entire foundation wall on all sides of your house for the best results but you can also apply these steps to the affected areas of the foundation and see if it solves your issues before doing the entire system.

 

• Dig out your foundation to the base of the footing.
• Power wash your foundation to remove all dirt and get it back to gray concrete (or brickwork)
• If your foundation is brickwork grind and repoint as needed following proper pointing methods.
• Make all repairs to spalled areas of your concrete foundation now using appropriate professional concrete repair products (BASF makes quality products).
• Strip away any old failing foundation coatings, membranes, or paints as needed.
• Repair all cracks in your foundation with backer rod and caulk following proper caulking procedures.  Assume all cracks are moving cracks so we want to honor them and not patch them with anything hard.
• Apply backer rod and caulk to any seam between the footing and foundation following proper caulking methods.
• Apply BASF Master Seal HLM500 liquid foundation coating to the entire footing and foundation
• Once dry you may opt to install a secondary waterproof membrane over top the foundation coating using rolls of 40 mil thick self-adhering flashing membrane made by Tamko.
• Overtop the Master Seal foundation coating (or over the 40 mil membrane if applied) install BASF 975 Drainboard with the filter fabric side facing towards the dirt and the plastic side facing the foundation.  Follow product data sheet for installation instructions.
• The drainage mat should extend down to the base of the footing and up above finished grade by at least 1”.
• Install 4” perforated rigid PVC pipe (with filter sock) in a bed of ¾” crushed limestone that is approximately 3” deep.  The perforations on the pipe shall point downward and should be at the same elevation as the center of the foundation footing.  The seepage pipe shall be encased with well-consolidated gravel and connected to a sump pit.  The base of the foundation draining mat should end just below (and to the side) of the seepage pipe so any watershed will seep into the perforations of the pipe and run to the nearest sump pit.
• Backfill the foundation with dirt compacting it with a gas-powered plate compactor every 12-18” in depth.  

Now that we’ve mapped out a plan to address moisture infiltration we need to focus on the interior of the walls.  As the foundation stands in its current state, it is constantly getting saturated with ground moisture and the wall will dry towards the warmest and driest side which is typically your basement side.  This drying-out process works perfectly well and is typically harmless to your masonry foundation unless the wicking process is disrupted somehow.  Applying any coating, plaster, or parge to the inside of a foundation will certainly trap moisture.  Even repointing brick foundations with hard dense Portland cement mortars can entrap moisture in the wall.  Entrapped moisture breaks down water-soluble salts that are naturally present in all masonry and these salts re-crystallize as concentrated deposits as the wall finally dries. You’ve certainly seen areas of masonry covered by these white powdery salts known as efflorescence.  Efflorescence that forms on the face of masonry is unsightly but it’s the “sub-efflorescence” that occurs just beneath the face of the masonry that causes significant spalling and flaking.

If you are going to waterproof the exterior of your entire foundation following the steps above, most likely the current issues you are seeing on the interior of your basement will stop immediately.  However, if you do not have plans to waterproof your entire foundation then all coatings and plasters should be stripped from the interior side of the foundation walls.  Even with 100% of the foundation waterproofed, it would still be best practice to only use lime-based plasters (NHL 3.5) or mineral silicate-based coatings (Keim Mineral Coatings) if you prefer a more refined interior finish.

Applying any type of insulation directly to your foundation wall is not recommended and is not a method that should be used without first completely waterproofing the exterior of your foundation.  A better method would be to fur out the walls so there is a 1” cavity between the foundation and the studs.  Insulate the stud cavities only and drywall.  Allow the cavity behind the studded wall to regulate the foundation wall, its due points, and moisture evaporation.

Interior exposed masonry such as brick and stone foundation walls and fireplaces are often heavily soiled with soot, dirt, and dust. We recommend Cathedral Stone’s Latex Based Cleaner, which is a poultice cleaner designed for interior use that requires no rinsing. Brush or spray on a thick even layer of the cleaner and allow it to dwell for approximately 24 hours until it dries. Once it has dried it will be rubbery to the touch and is ready to peel off. As you remove the poultice it will pull the accretions off with it. This cleaner removes surface soiling, so it won’t mitigate rust or penetrating stains.

As always, do a small test panel before a full application. Samples are available in our shop and we carry a limited stock of cleaner in one and five-gallon pails, so call to check stock before coming to purchase.