Loose bricks

[cart]

Hi all,
my house was built in about the late 1920's,the house is weather board and sits on bricks stumps with a bricks running around the house which the frame work also sits on,in one corner I have noticed several bricks very loose and if the frame work sits on this there is no weight on them, as the top few bricks move easily,there are about 3 layers down of bricks loose by about 4 bricks long( hope that makes sense)

How can I fix these loose bricks,would I scrap any loose mortar out and fill that gap with mortar or remove all the loose bricks and put them back in with fresh mortar.

I know the house could do with restumping,running a spirit level along the floors tell me as such,but that is not an option.

Any help would be appreciated.

Thank you

Cart

[addo]

A layer of bricks, as you described it, is called a "course".

The looseness is possibly the result of mortar fretting (erosion), or a weak mix, or inadequate bond (frequently due to poor curing when laid). Your mortar will be lime mortar, possibly mixed with locally milled sand.

If the brickwork has dropped, this usually reflects the changing environment around the building and an inadequate footing. Not to worry; work with what you have and results will be fine.

The worst thing you can do is to stuff any of those "instant" mixes into the cracks. Next worst is to use regular grey mortar mix sold by the bag...

Sounds like up to 12 bricks are loose. That's probably a decent amount to remove and re-lay yourself. The mortar spaced between bricks is known as "jointing" and maintaining an even joint is part of what will try your patience at first. Lightly number the bricks with a pencil before removing them, and scrape old mortar 90% off with your trowel. Bricks are stored on edge, which keeps the top and bottom surfaces clean.

By volume, try a mix of 9 parts "white brickies' sand", 1 part off white cement, and 1 part plasterer's lime (not ag lime). The sand might take a little searching; at a pinch regular brickies' sand will do if it's not too dark. Dry mix the ingredients, and then add water to make a smooth mud. I'd suggest experimenting a little with small mix quantities and one or two bricks, rather than going for the kill.

Also, if you're not used to bricklaying, a pointing trowel may be better than a regular brickies' trowel. It's smaller and easier to handle, and does the old style "weatherstruck" pointing nicely.

The mortar mix above, can still be easily knocked apart and cleaned up a day or two later. Smears of mud can be sponged or damp brushed off while you work - or an hour or two later.

If you can get to the offending corner under the house, try using a car jack on a small pad of ¾" ply, to push the house up slightly in the short term. Make sure this can't vibrate loose - pin with screws or nails as needed. Keep all fingers out of the danger zone while working, and lay your bricks up closer to the raised wall plate than before. After a week, let the jack down and the frame should be resting on the newly fixed wall.

Cheers, Adam.

[cart]

Thanks Adam,
excellent info for me to go on, I can get under the house to get into the corner so will be able to work from the outside and inside.
Thanks again.

[Brickie]

What he said.

Although the mix should be 6:1:1

[addo]

That's where we'll usually disagree. As it's an older house, you could use the NSW Heritage Office publication "How to Carry Out Work on Heritage Buildings and Sites" (Revised 2002) as a guideline.

The only time they suggest 6:1:1 is "Severe exposure", which I would take as meaning subject to a bit more than lashings with rain... "Moderate exposure" which I would take as below DPC on a typical older house, they recommend 9:2:1 (Sand:Limeement). Might be better than the 9:1:1 I proposed first up.

Cheers, Adam.

[Brickie]

The only time they suggest 6:1:1 is "Severe exposure",

Severe exposure to what, rising damp?

TAFE Certs 3 and 4 (Carpentry, Building), Fair Trading registered chippy.

I always love the way wood butchers seem to be THE know all and end all to the building trade, especially when its outside of their knowledge of expertise...

Just do what Addo says, hes the expert..

[addo]

Look at it positively!

Cart has two points of view to chew over. Plus he's just been given an exemplary lesson in the dynamics of how trades interact.

[cart]

Thank you both.

If I may ask one more thing.

Because of the colour of my house and living adjacent to a highway,there have been times when I have pressure cleaned the house as an accumalation of road grime sits on it.I have used the spray setting on the nozzle and not the stream side of it.

When the water has run down the weatherboards and onto the brick it has washed out the mortar

Your mortar will be lime mortar, possibly mixed with locally milled sand.

, could I render over this filling in where the mortar has gone with the render as I go along,there are no bricks loose only the mortar gone.

Have I opened a pandoras box as i really did not take much notice of the brickwork prior to noticing these loose bricks.

Footnote:A ha should i follow this.......link http://www.brickwork.net.au/Repointing.html
sorry guys just read this after posting

Thanks again

Cart

[Brickie]

, could I render over this filling in where the mortar has gone with the render as I go along,there are no bricks loose only the mortar gone.

You can render over it, it all depends of the finished look that you are after.

Render is usually done with washed sand not brickies sand and the mix strength is usually higher, I dont do render so I wont profess to be an expert, maybe someone else can answer it for you.

[Make it work]

I have exactly the same problem and thought of rendering to solve the problem so I am also keen to hear opinions too.

I was told the problem was caused by salt from the ground but I am not sure of this.

[Brickie]

Over time salt will destroy brickwork if left unchecked.

Here is a pic of brickwork from the 1890's that has been eaten away by salt.

Old bricks are a lot softer than their modern counterparts.

[cart]

Thanks Brickie thankfully mine are not like the pic u posted and only the mortar requires repair,the rendering would kill two brids with one stone for me as I intend to render over the bricks once the mortar is done.

Cheers

[Make it work]

I was reading about this, old lime mortar was soft and remained flexible and cured very slowly. It also was designed to offer the path of least resistance for rising damp and fret away rather than the bricks, the logic was that it was easier to repoint rather than replacing bricks.

[Brickie]

Lime mortar was all they had, thats why they used it..

[addo]

There was ground Portland cement, but in the era of Victorian building it wasn't much used.

I think it was probably a greater cost proportionally, and also, as the concepts of "how to build" were different to now (more inclined towards floating footings, for example) then its application wouldn't have really solved many issues. Sometimes you see cement render up to DPC level on façades from mid-Victorian through the 'teens.

Since these earlier eras, we've become much more demanding of neatness and durability of work. If you look hard at brickwork on the outsides of a 1900 house, it's pretty rough! Try serving that up to a customer in 2007 (I'd be ecstatic, but Mr and Mrs Average would have a pink fit).