Makers of the Brick Brace claim it will help you gain fitting space, reduce repair time and achieve a superior and safer finish when undertaking masonry alterations. Roger Bisby takes a look.
Most builders hardly give a second thought to knocking away supporting walls and propping them with a small forest of screw-jacks or Acrows as they are generally called.
Structural engineers give us long hand calculations for the steels but hardly ever bother with guidance on how we support the structure temporarily. Like many people reading this I have been carrying out such jobs all my working life, sometimes taking away the entire back end of a house and the three floors above it.
My approach has always been to get in as many temporary supports as I have room for while realising that if you are to get the steels in you need room to work. That is always the trade off. Of course the best way is to have that steel positioned by the wall and to cut out a neat slot that stays open for the shortest possible time. That is the theory but there are times when you have to bend your own rules.
Often this requires you to support the opening from one side only with Strong-boys and that is where you can really start to push your luck. The tongue of the Strong-boy extends through to pick up both skins from one side but anyone with an elementary grasp of physics will know that the end furthest from the prop is not going to be as well supported.
anyone with an elementary grasp of physics will know that the end furthest from the prop is not going to be as well supported
In fact if you take the trouble to read the tables and guide lines for this type of prop you will see that they support surprisingly little in terms of tons. Hopefully the side best supported is the internal wall which is usually taking the load from the roof and floors but I have seen it done the other way round.
I remember clearly the time when I saw a gang of over-enthusiastic under-pinners lose the back addition of a house, it listed and opened up a gap of 30mm at the top. But to top that a builder (property speculator) I knew had a whole stone built house collapse, almost on the stroke of midnight. His men had spent the day removing internal walls to create that front to back open plan ground floor that everyone seems to like these days and the next day the house was a little more open plan than they had bargained for. The whole thing came down like a pack of cards and covered three streets in dust. From time to time you also hear of others coming badly unstuck with fatal consequences. Accidents of this sort are a lot more common than you might think especially with cellar dig outs. It has probably happened in most localities so you will probably have your own stories to tell.
a builder (property speculator) I knew had a whole stone built house collapse, almost on the stroke of midnight
Even if nobody is injured you may still find yourself under a great deal of scrutiny, not least from the insurance company. Did your risk assessment and method statement have the input of a structural engineer? If you are a small builder/ house basher, then the answer is probably no.
If you do get a structural engineer involved at any stage you will probably find that they will not allow the wall to be propped by screw-jacks alone. In many cases they will ask for structural scaffolding supports to be used as a way of tying all those loose Acrows together so they act as one. This can also prevent props from being knocked out accidentally,as often happens. This was the starting point for the development of BrickBrace, a temporary support system that can be used to provide additional support for openings when you are removing supporting walls.Before you even begin to remove any structural elements you can cut out the perps put in expanding steel wedges and tie then all together with steel scaffolding poles.That way the wall is put in tension and tied together.
The Brick Brace system can be used to tie screw-jacks together to stabilise them and make them act as one or it can be used to provide the sole support for openings up to approximately 3 metres.
As most builders know the critical area of brick that needs supporting is a triangle above the opening but if that triangle is interrupted by a window or door then the support needs to be recalculated as two or more triangles. With the Brick Brace system you can put in two or three tiers of support and it is proving to be a very popular item for underpinning firms.
the critical area of brick that needs supporting is a triangle above the opening but if that triangle is interrupted by a window or door then the support needs to be recalculated as two or more triangles
Accidents aside there is also the possibility that the brickwork may move slightly during the propping stage and that then gives you the added hassle of re-pointing it and repairing any internal cracks. When the steels are in and properly supported on the pad stones or steel posts it is hoped that the structure will be stronger than it was before the alterations, certainly that has always been my goal when carrying out this kind of work, but, like most builders I am happier when the steels are in and the brickwork above is nicely wedged up.
The use of the Brick Brace system gives you added peace of mind not least because it is all tied in to act as a single unit. It takes up no room in the van and is always there when you need it. Personally I would still try and use steel screw-jacks where possible and any other support I can bring into play because, if ever there was a case for belt and braces, knocking out supporting walls is it.