Wet Weather, what happens to bricks and brickwork?

Brick & Wet Weather

Construction and wet weather are NOT a match made in heaven. This is particularly true when the job is coming out of the ground or you don’t have a roof on.

I’m sure you know that wet weather affects all external trades including bricklayers. Wet weather has some specific issues in regards to bricks & bricklaying & that’s not including delivery, which I’ll leave for another time.

Now I’m no technical or scientific guru. But I do have 30 plus years of experience working within the building industry, in particular distributing bricks. I know from experience what happens to bricks and brickwork during times of wet weather.

Ok, so I’ll paint the picture. The job is underway, bricks and sand are on site, and you’re waiting for the brickies to start in a day or two.

Oh oh, the heavens have opened up and delayed the bricklaying for few days. I hate to say this, but that could be just the beginning of your issues. All brickies know that you should cover your brickwork and bricks on site. Effectively keep them as dry as possible. Wet bricks are a bugger to lay because the bricks rely of the absorption moisture from the mortar to hold them together. If the bricks are wet they won’t absorb enough moisture from the mortar to “stick” them together.

‘So what’ you say? ‘What’s the big deal’?

For starters, the brickies will tell you wet bricks will float because the bricks can’t absorb any more moisture from the mortar. Which means they will lose their bond and more than likely the wall will come and go out of plumb.

But wait, there’s more.

Some bricks are susceptible to excess moisture, particular light coloured bricks. One issue is Vanadium staining. To explain, all bricks have a salt in them referred to as Vanadium. When these salts are exposed to acid (rain water is slightly acidic) these salts turn yellow. This “stain” whilst unsightly can be treated, but I’ll leave this for another time. Right now I’m trying to help you avoid any unnecessary work and costs.

The below image is an example of mild vanadium staining.

On top of this, wet bricks look darker so if you have a “blend” of colours in the chosen bricks it makes recognizing this blend much more difficult. I have seen jobs laid with wet bricks and when the bricks dry out, the brickwork looks like a patch work quilt. It’s not pretty and it’s not right.

Also remember there is another component of brickwork yet to be discussed – sand. Laying wet bricks with sand that is saturated is also a problem aside from the bond and plumb issues. If you lay wet bricks with wet sand subject to the mortar finish (ironed or raked) I can almost guarantee you that when the mortar dries out it will also be different colour across the brickwork. And yes I have seen this many times, in fact there is job around the corner from me that started in October, brickwork started late November and then the heavens opened. That brickwork is now completed and its appearance is terrible. Brickwork itself looks ok, but the change in colour of the mortar every meter or so up the wall is horrendous.

I’ll be really surprised if the owners are satisfied. An important thing to note is that the mortar is approx. 15% of the brickworks appearance. So discoloured mortar has huge bearing on the over colour and finish of your brickwork.

See the image below of the type of surface mottling of mortar joints.

Ok so what should be done when the weather turns sour?

  1. Cover all bricks and brickwork. When moisture penetrates into the brickwork by the core holes it can take a very long time to dry out.
  2. Cover the sand to keep it as dry as possible.
  3. Do not lay more bricks until the bricks and sand are dry (this will be much sooner if they are covered).

I get it that time is of the essence in building. But I’m sure you also know, shortcuts have consequences.

Hope this helps,
Martin D.

1 thought on “Wet Weather, what happens to bricks and brickwork?”

  1. Hi martin
    I was just reading your article about wet bricks , my son is building a house, it’s been 12 months, the slab is down, and the bricks have been delivered, no bricks have been layed yet, they have been out in the rain for 10 months, seen 2 winters , the bricks are soaking wet and have got green algae on them , has he got the right to refuse the bricks because of there condition, and who’s responsible for them to be covered up

    Many thanks Dean

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