Timber / brick fill

[TBHG]

Hello!
Please can I ask for advice? See photos x 2 (for some reason these seemed to have rotated 90 degrees on posting, the beam is horizontal!)
We have a 16th C timbered cottage, which was heavily renovated in mid 20th C (prob post-War 1940s) which included (I think) removing the original panels and replacing them with brick in-fill.
On inspecting a panel that was peeling, I noticed the timber was rotted at the bottom edge approx 1-2cm. I have removed the cement & rot and there is now a gap. (see photo)
So my questions are:
Presumably I should re-point with Lime mortar rather than cement. What type of mortar should I use?
Secondly the brick in-fill seems to be cemented rather than lime mortar set, which would I guess be right if it was 1940s in-fill. It has been painted over with masonry paint (several coats). Given that the brick/cement is I presume pretty impervious, is there any point in lime rendering this, or should I just paint it back over with mortar paint (but not painting over the new lime pointing).
I am trying to "repair sensibly" rather than start a big renovation job which I don't have time or money for right now!
Many thanks for any advice.
Jon

 

[plasticpigeon]

Lucky you caught that I reckon! Not much damage done by the looks of things. I personally would be tempted to use a trowel mastic which is basically sand and linseed oil. It should stop water ingress and be a bit more flexible than a mortar. This is what is often used to bed timber windows into brick reveals and to point up the gaps around wooden windows. I have linked to an example of the mastic I am talking about.

http://www.everbuild.co.uk/index.php?route=product/product&product_id=163

Plastic masonry paint tends to peel and flake after a while. Other options don't peel and flake so they might be better. I know others on here know better than me.

 

[Feltwell]

If you were going to try a trowel mastic, I wouldn't bother buying it, it's so easy & cheap to make "burnt sand mastic" up yourself. See this old thread, or search burnt sand mastic on here for others.

http://www.periodproperty.co.uk/for...2889&p=174361&hilit=burnt+sand+mastic#p174361

I made up a batch recently and forgot that I'd used boiled linseed oil before, this time I used raw linseed oil instead. It seems to have gone off a lot quicker, time will tell if it's as durable.

I would have thought that a bit of lime mortar would be fine to fill that gap though.

 

[TBHG]

Thanks both
So which would be better & more durable - lime or mastic?
Also any thoughts on the brickwork, shall I just masonry paint it again (which would be easiest!)
Jon

 

[El Greyo]

How permeable is mastic? If it's oil based I assume not. Rotting timber is often caused because water can seep into the wood somewhere (and it's very difficult to prevent all water ingress) but is then trapped. I would have thought that as lime mortar will allow moisture to escape then it is the better option.

 

[plasticpigeon]

I'd be wanting to stop any water ingress between wood and brick and would have thought the mastic would be better at that.

 

[El Greyo]

I'd be wanting to stop any water ingress between wood and brick and would have thought the mastic would be better at that.

If you can prevent 100% of water ingress (from any source) then that would work. But in reality it is pretty much impossible, the mastic will restrict the escape of moisture, the wood will be much slower to dry and will be more likely to rot. We own a timber frame cottage with brick infill, the previous owners had used cement around the timbers (and sometimes over them) and many were damp and rotting. We have stripped out the cement and replaced with lime mortar and now they are dry. I'm very happy with this method.

 

[plasticpigeon]

Well if you've had success with lime mortar that is a good reason to use it in this instance too!!!!

 

[skier-hughes]

They use the same linseed oil in linseed oil paint which is very permeable, so my inexpert guess would mean that the mastic would also allow water to get out??????