Brick and stone Mortar deteriorating

Hello to all. I have a question I’m hoping someone can answer. I inspect homes in the North East. What’s happining when the mortar between brick and stone deteriorates, even the face of the brick is deteriorated to a depth of aprox. 1/4" to 1/2". On homes with brick or stone foundations, and a considerable amount of effervescence on the walls and the mortar is all but gone, turned into dust - what is the fix and what can be done to stop the deterioration? What is causing the problem? The bricks are about 50 years old.

Short list, hope it helps.:slight_smile:

Expansion and contraction due to freeze/thaw cycles

Expansion of soluble salts – efflorescence

Thermal expansion and contraction

Expansion of rusting metal contiguous to the masonry units

Painted masonry – moisture trapped in the masonry may not be able to escape

Masonry “sealed” with an inappropriate sealer

Effects of acid rain

Failure to properly repair mortar joints (repointing) soon
after initial mortar failure

Using an incorrectly formulated repair mortar for repointing

Failure to repoint

Incompatible materials with differing physical characteristics contiguous to each other

Imperfections in the masonry units from the fabrication or manufacturing process

Masonry units installed incorrectly – poor workmanship

Poor detailing, design and specifications

Wind erosion

Biological growth – plant life

Rising damp – the vertical migration of water through masonry by way of capillary action

Splash back – water falling from the roof line, impacting the ground and splashing against the masonry

Impact from vehicles etc.


Birds and other mammals

Often, several of these forces work simultaneously on the masonry. It is only after the cause has been determined that the best appropriate repair can be recommended.

Pictures would be handy to view if any.

Masonry in the NorthEast have many variables and a lot of speculation can be made and that is all they would be.

Let us start with the mortar that could have been used;

**M A S O N W O R **K

The underlined letters indicate the type of Mortars that can be used and also spells who is doing it.

Each type of mortar plays a great roll in what is expected of a masonry facade.

Then comes the type of brick or stone.

Once this is established one can continue to the Building Science of the Trade and Building Envelope.

If there is visible problems as witnessed in the inspection, I would note it as such, reccommend a Masonry Contractor to evaluate and move on.

Wish I could help more, but this would be to long to list.

Marcel :slight_smile: :slight_smile:

Thank you for the reply information. I told my customer just that. The problem is bad enough that they need to have a qualified contractor evaluate the situation, then I moved on.

Brick deterioration generally occurs in one of two ways…

  1. Spalling and deterioration. Spalling is caused by moisture getting into the brick, freezing and 1/8 inch to 1/4 inch of the surface separates and falls off. This damage will be apparent, and the remaining part of the brick will still be relatively hard.

  2. Deterioration of soft brick looks like it is being worn by natural elements. This is typically a salmon or an orange, clay brick that was intended for use on the inside layer of a solid masonry wall.

Spalling and/or deteriorated bricks can be chiseled out and replaced. In an 8 inch wall, you might easily take out 20 bricks at a time without serious concerns about the structure. Consult a structural engineer if the damage is extensive or if you are unsure.