Brick hardener - any good?

[Lindyboo]

We have a number of soft exterior bricks in our cottage. Some of them are coming away in flakes and others are more powdery. They’re not the majority by any means, but clearly are past their sell-by date. I’ve seen some ‘brick hardener’ which claims to bond the soft material. Anybody used this stuff?

 

[Nemesis]

I suspect this is some sort of resin?

 

[biffvernon]

Curiously, "brick hardener" returns no results in Google UK and only 21 in Google Web, mostly in foreign languages. It does produce a couple of results associated with the repair of refractory bricks for kilns and some adverts for resins.

 

[Lindyboo]

Well, now I'm perplexed. I saw this stuff last year in the Screwfix catalogue, but I now blush to learn that it is no longer offered. As Biff observes, no mention of it on the web either. I was tempted to buy the stuff at the time and now wish I had, if only to show that it did exist. Such are the dreams of the everyday housewife ... However, is there a remedy for soft bricks? Can they/should they be removed and replaced? (Unlisted building, btw). I have half a notion that it's possible to carefully chisel out the offending item and replace it with a sound one - am I correct? We have - literally - tons of old bricks on site, due to some past demolition of outbuildings, so it should be easy to find good ones that match.

 

[biffvernon]

You have to decide whether the effort is worth it. It may be easier to just ignore a soft brick until is disintegrates completely. Meanwhile you get a fair bit of drinking time.
There is an electric tool, whose name escapes me, that has an attachment that cuts the mortar out deeply round a brick making the job quite possible if you must.

 

[Ian Bond]

I can't speak from experience with brick, but have similar problems with stone. That's if you consider it a problem - some are flaking/crumbly but not too bad.

I have cut out and replaced the odd one or two stones where previous bodgers (I mean craftsmen) had put pipes etc through the wall and made a mess.

I tend to agree with Biff - leave them alone as far as possible, but if you must you can cut the odd brick out carefully and re-bed and point with a matching lime mortar.

SPAB (naturally) offer some good advice on the subject, which Biff has pretty much summarized perfectly:

http://www.spab.org.uk/html/advice/...k/?PHPSESSID=e0f6f11aa44f97e2a602fa0ccb20bfd4

 

[biffvernon]

There is some controversy over the efficacy of soaking crumbling stone in limewash, the theory being that calcium carbonate crystallises within the pore spaces and strengthens the stone. Depending on the stone and how it's done it may make matters better or worse.

 

[FamilyWiggs]

Well, when Itype "brick hardener" on Google, I get the following on the first page amongst others:

http://www.andek.com/H%20POLASEAL%20PENETRANT%20HARD.htm

http://www.trade1st.co.uk/productdetail/HARDENERSTABILIzINGSOLUTION/334.aspx

Personally, I'd learn to live with a few crumbly bricks, or replace them as suggested above. Either way you should identify if there is a cause/contributory factor to the crumbling (eg dripping gutters) and fix that too.

 

[chuckey]

On a victorian garden wall (110' long by 6' high), I have 3 crumbling bricks, on another slightly more modern wall (Edwardian?) I have a few more. From the above, it would seem that that a miniscule amount of the bricks suffer from this. The bricks them selves are all very soft, a builder called them "red rubbers", so I wonder if the real problem is in the mortar surrounding them, because my theory is that they are self draining, they soak up a lot of water but it all runs out, so there is none left for the frost to freeze and cause the face to spall. If you put a bed of impervious mortar around and underneath them, this would inhibit the water draining and so they would spall with the frost. If the lime that was used had the correct clay impurities, it would be a hydraulic lime, i.e. water proof. So I am postulating that the mortar around these spalling bricks could be trapping the water, so a cure would be to drill some drainage holes halfway through the mortar course making sure that the the underneath of the spalling brick is open to drain.
Frank

 

[Lindyboo]

Re Frank’s mention of the type of mortar. I’m in a state of grace about it. I know from reading this board that lime mortar is considered the right stuff, but I’ve never seen – or more accurately, never recognised – lime mortar. I’ve assumed that, since the succession of herberts who’ve messed about with the place made such a rough job of everything else, the existing mortar in places is probably the lime variety, and elsewhere is modern stuff which has been gobbed in by the trowel-load. Certainly there is plenty of variation in appearance of the mortar. What should I look for to determine which type, or more likely, types, of mortar have been used?

 

[chuckey]

Lime mortars always have a white look about them, look for white spots where the lime has not been mixed properly. Cement is grey so cement mortars go from bluegrey right through to the sand colour alone (when the mix has less then 15% cement in the mix). NOTE no white. Also lime mortar is much softer then cement mortar, but you will have to chip/scrape two bits to compare them. Really old lime can be brushed out with a stiff brush.
Frank

 

[Craig]

I thought the weeze was to cut a brick out and turn it around so you get a "new" face on the outside?

 

[DaveBrigg]

We have - literally - tons of old bricks on site, due to some past demolition of outbuildings, so it should be easy to find good ones that match.

Hmmm. I started removing the cement render last week; on the Georgian parts the brickwork is generally sound but the earlier tudor stuff had large patches which turned to powder when breathed on. The problem was especially severe around the windows, which have been cut into an existing wall.
The cement is thought to be Victorian, and in places was a couple of inches thick, so the bricks must have been crumbling before then. This is possibly why the house was rendered in the first place. There's not enough left to turn the bricks round, and they can be cut out with an HB pencil. So if anyone knows of someone living in the Lincolnshire area with a few spare bricks on site, and willing to make a deal, could they let me know :wink:

 

[Ian Bond]

interesting that the brickwork has fared worse around the windows. It's happened to my grit-stone house too. The edges of the stone at the window reveals have eroded in places, but the outer faces are fine.

Turning bricks around is indeed a good trick, as mentioned by SPAB in the link above - but obviously you need enough brick left to turn in the first place.

 

[Lindyboo]

[quote So if anyone knows of someone living in the Lincolnshire area with a few spare bricks on site, and willing to make a deal, could they let me know :wink:[/quote]

How many do you need?

 

[DaveBrigg]

50 - 60 would be great for a start, maybe a few more if there's time to complete the Tudor barbecue in the garden. Having puzzled as to why the window reveals have suffered so badly, I suddenly realised the rather obvious point that the brickwork has only crumbled on faces which were originally exposed. i.e. the edges with mortar are generally in better shape. There is nearly an inch gap between the wooden frames and the brickwork, so these bricks would have had two adjacent faces open to the air, even if not directly exposed to the elements. Either that, or the bricks were damaged when the hole was cut for the windows, allowing more moisture in.

 

[biffvernon]

Tudor barbecue ?

 

[Lindyboo]

50 - 60 would be great for a start

I'll have a mooch around the garden later today or during tomorrow and see what's doing. Most of the bricks have either been hurled into the hedges or have been laid in a poor attempt to create pathways. Some have exposed faces where they've been used to make raised borders (stacked loosely, not mortared), so those will be the easiest to examine and remove. I was intending to offload some onto our farmer neighbour who needs to fill in part of a dyke and the others, apart from a few to replace the crumbly ones in our walls, were destined for the skip, so I've never cast much of an eye over them. Will get back to you.

 

[biffvernon]

Just before too many dyles get filled in, I'd like to point out that old bricks can be worth from 50p to £1 each, more for some specials.

 

[DaveBrigg]

Whereas old cement render is a pain in the proverbial. If there's an old dyke that needs filling, I'm your man.