Cement mortar in older property

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Can cement mortar be used with soft bricks in older property?

FreeBear

genau wrote: »

Is it acceptable to use cement based mortar in soft brick house walls on the outside part when replacing some brickwork or does it always have to be a lime based mortar?

The house dates from 1915 and is constructed of soft red brick

If you use cement mortar, it will eventually crack and fall out. The bricks will also be more prone to spalling. The cement pointing will also stand out like a sore thumb.

You can purchase ready mixed lime mortars colour matched to your existing mortar. A bit pricey, or you could go with an off the shelf mix that is a close match.

A 1915 property is most likely solid brick, so do yourself and the building a favour and use the right materials. Future owners will thank you for it, as will the house.

konark

My 1915 house had cavity walls.

FreeBear

genau wrote: »

What is the significance and implications of replacing brickwork in a soft brick exterior wall circa 1915 where cement based mortar has been used instead of lime?

As before. The bricks are at a much higher risk of spalling over time.

There was a brick wall at the end of my road. It had been constructed from Norfolk Reds (a soft friable brick) with cement mortar. Over the years, the bricks degraded and eventually, the wall was just a honeycomb of mortar with a few bricks hanging on.

One advantage of using lime based mortars - If you need to reclaim bricks, they clean up with very little damage. With cement, you may as well feed the whole lot through a crusher.

FreeBear

genau wrote: »

Although the work wasn't extensive it still cost a lot of money. how serious is the problem and should I get this redone or is it acceptable to leave this as it is for the time being?

Is this something of a matter of debate with some people having different opinions on the subject or is it a case where there's no room for debate and this is just plain black and white wrong which any good builder will agree with?

You said it was three areas of approximately 75 bricks each - In terms of square feet (or metres) at double thickness, it isn't a large area. In time, I would expect the bricks to degrade, but it will be thirty years or more before you'd need to think about replacing them. Plenty of time to scavenge some replacements.

As for "right or wrong way", it depends on who you talk to. The people who spend their lives caring for and restoring old buildings will say "use lime". The average builder who doesn't know any better will say "whack a bit of cement in" - It goes without saying that he will be long gone before the problems start showing.

I'm in the "use lime" camp - Whilst the materials are a little more expensive, it is so much more forgiving. I have plaster mixed up over a year ago, and it is still good to use (made with marble powder & lime putty). Mix a batch of mortar with NHL3.5, and you have a day or more to use it up.

It would be worth your while visiting http://www.periodproperty.co.uk/forum/viewforum.php?f=1 - A veritable mine of useful information, and a helpful bunch of people.