Setting out a conservatory on a pebble-dashed bungalow

[realtek]

Hi,

I am trying to square out a dwarf wall for a conservatory against my bungalow (so it will have a hipped back roof attaching to the gutters etc...)

The problem is, our bungalow has pebble-dashing on it making it very difficult and to be honest, i'm not sure what I am best to try being square with.

I know the 3-4-5 method etc and principles.

I have remove the pebbeldash down to the scratch coat/cement but still not getting even measurements to square up with the bungalow.

I have already poured the foundations and everything was going good until I realised I was not 100% square with the house, its only mm that I need to move by and there is plenty of foundation to play with.

I have tried taking my measurement directly from the bricks near to foundation level and I have a complete parallel far line across which I checked with a plumb bob but something isn't right because the two other lines cannot be made longer or shorter because one will either be too far away from the house and the other will be too close.

My question is, with a pebbledashed bungalow what is the best thing to try and get square with and what to other people normally too? Or perhaps i'm worrying too much about being square with the bungalow!

Removing the scratch coat to expose brick is near impossible.

Its also an old bungalow, 1940's ish

Any advice welcome!

Thanks

 

[^woody^]

Set out off the bricks below DPC.

Form a parallel line to the house, representing the depth of the conservatory.

Then set out a line representing one side of the conservatory - square off the house and square off the line parallel to the house.

Then set out a line parallel to this side line, to represent the other side of the conservatory.

Then use a tape to check the diagonals between the corners.

 

[realtek]

Thanks woody.

I will try tomorrow taking a line down the side of the bungalow (as it is detatched) and line it up with my line that is already parallel to the bricks below the DPC (going across) and hope this is a fairly good right angle. I will then set up the other line again and check the diagonals.

I forgot to mention, the bungalow actually has pebble-dash below the DPC (and bridging the DPC) which does not help matters.

So the only bricks exposed are the ones below ground in my trench.

I am not sure how accurate it will be taking a line down the side as this will also be over the pebble-dash but I will give it a go unless you have any other ideas. I have spent hours on this! lol

Thanks

 

[^woody^]

Knock a patch of render off where the the new walls will abut the bungalow below DPC. Don't trust the bricks below ground.

I would do all setting out from the back elevation and don't bother messing about trying to align things with the side

Work from one elevation or reference line only

 

[realtek]

OK great thanks. I will give it a go and let you know how I get on.

I agree with not trusting the bricks down there, I expect thats why things didn't line up above, It seemed as if the wall was not plumb with them.

I will try and knock it back to the bricks in a couple of places (That'll take me a day or so lol), got any tips on getting it off?

I usually use my SDS with a chisel on it but it won't get the bottom coat off as its very solid and then goes too far and take a chunk of brick off with it.

Will have to stick with it and keep going.

 

[theprinceofdarkness]

My recently aquired bungalow is "U" shaped, so I thought its begging to have a conservatory built in the gap. When the guy turned up to measure with his laser what-not, we discovered that the floor level each side of the U was 25mm out and the sides splayed by 30mm. I think that building the conservatory slightly out of square on the plan will only result in the floor tiles showing the error. However if the verticality is out on the rendering, as the door, and all the glass will be square, any error greater then 3mm will show.
Frank

 

[realtek]

Knock a patch of render off where the the new walls will abut the bungalow below DPC. Don't trust the bricks below ground.

I would do all setting out from the back elevation and don't bother messing about trying to align things with the side

Work from one elevation or reference line only

Hi Woody.

Spent a day over the weekend removing pebbledash and the render right back to the brick on both sides.

Then could see the bricks on one side above the DPC were hanging off the DPC. Looks like the wall below the DPC near one side has collapsed in (probably lack of infill). I have taken the measurements off the wall above the DPC as all appears to be plumb. So I have squared everything off based on that as the line and everying is completely square including diagnosed and 3-4-5 on both corners. I am happy with that now.

When I build the two sides up to the roof I will probably take the gutters/facias etc off and pack it out behind and get the roof square with my building but it looks like it may just be the pebbledash as to why I am not seeing the soffits as square.

Would be a better route rather than having the conservatory guys pack out the conservatory in my opinion.

I will start laying the blocks when I have time in a couple of weeks!

Thanks

 

[realtek]

My recently aquired bungalow is "U" shaped, so I thought its begging to have a conservatory built in the gap. When the guy turned up to measure with his laser what-not, we discovered that the floor level each side of the U was 25mm out and the sides splayed by 30mm. I think that building the conservatory slightly out of square on the plan will only result in the floor tiles showing the error. However if the verticality is out on the rendering, as the door, and all the glass will be square, any error greater then 3mm will show.
Frank

I agree Frank, any defects with being square will probably show up on cosmetics rather than causing major issues when fitting. The only exception is the roof but as i've heard, they tend to just pack this out to get it to fit. Any part of the conservatory being secured to the actual bungalow will always be filled with silicone anyway so being square won't necessary help water proofing it.

With ours I will be building a new patio in front of it too, so I guess 3mm or so over the course of the projection of the patio could end up being quite significant and therefore the patio tiles etc may go off course (especially if your close to the boundary), so that was also part of my preference to get it quite square but its never going to be exact.

 

[^woody^]

The frame can be jigged about so that any discrepancies are taken up at cill level with slight differences in overhang.

But you'll do yourself a big favour by having at least three sides square - the new walls.

 

[realtek]

Hi Woody,

I will finally make some progress this weekend and start foundation block laying.

One question, since I exposed the house DPC. Because its an old bungalow the DPC is slate.

The thickness of the mortar joint with DPC sandwiched in between is 30mml

My question is, should the top of my bricks go up to the top of there bricks or do you advise going higher?

My gut feeling was to stay at the same level with the bricks and just put my DPC up the wall a bit to meet theres and carry on or should mine be higher? Its not quite possible to go midway and make the two DPC's at identical level because its not even along the DPC course and is all over the place.


Thanks!

 

[^woody^]

Keep the brickwork level. Your new DPC will be bedded on 10mm of mortar, and it will have a 10mm bed on top, and the remaining 10mm will be lost in the blockwork.

Really you should lap the new DPC over the slate (disc cut a slot or drill several holes) but if you remove some render and run the new DPC up the wall 200mm or so and its pushed tight against the wall then that tends to be OK - if the existing ground is not constantly soaking.