Dilemma while moving a doorway

[oldbutnotdead]

Background- 1820 house, solid brick walls (by design, not by nature). At the end of the landing is a small cloakroom 1700 wide x 1100 deep- just about big enough to squeeze a shower, WC and basin in but very very tight.
Cunning Plan- move the bedroom doors 600mm towards the staircase (the landing is quite wide), make the cloakroom bigger (1700 wide x 1700 deep), have quite a nice shower/WC/washbasin space with room for the door to open inwards even.

Above the doorway

• oldbutnotdead
• 19 Jan 2015
• 1

Look at the pretty cracked bricks

LH purlin

• oldbutnotdead
• 19 Jan 2015
• 1

And check out the comedy plinth supporting the LH purlin

RH purlin

• oldbutnotdead
• 19 Jan 2015
• 1

Slightly better plinth but still a bit rubbish

RH purlin 2

• oldbutnotdead
• 19 Jan 2015
• 1

Cracked bricks following the 45 degree loadline (ish) down to the doorway.

Problem- pics will illustrate. I was going to needle the wall at the course above 2100 (to give space for a 100 x 100 steel lintel), cut away the righthand wall to where I want it plus a 200mm bearing for the lintel, build a block wall in the lefthand side of the existing doorway topping at 2000 to sit the lintel on). Problem is the brickwork behind the (flat) plaster has cracked- pretty much along the 45 degree load line for the purlins. So I suspect that the centre bit of wall above the existing doorway is not really doing anything useful (and isn't particularly stable) and the load from the lefthand purlin is mostly being carried by the existing wooden lintel.
So cunning plan 2 is to

• Directly support the purlins with a pair of acros on each

• Once the purlin load is supported by the acros, give those rubbish brick piers and the centre lump of masonry a shake.

• If they move/come apart then dismantle between the cracks down to above the door, cut away 600mm on right, build 600mm blockwork on left, insert lintel, build block/brick all the way up to support the purlins. Leave for a couple of days to go off then do the other side of the landing.

• If they don't move then needle as previously described and insert lintel with lots of anglegrinder action to compensate for the non-level courses

Before anyone panics about subsidence, the structural survey (and other clues) suggested historical moving and shifting- the wallpaper that was on that wall was at least 50 years old and completely flat so any movement was a long time ago.

All comments/suggestions gratefully received (apart from 'wtf possessed you to buy the place' )

Ta

 

[ree]

Without a plan view its difficult to visualise your proposal - perhaps scan a sketch? It would also help if you could mark outlines on your pics.

 

[oldbutnotdead]

Good point- I'll try that now.

 

[oldbutnotdead]

See if these help clarify the job- if not then I'll have to do some better pics tomorrow. Sketch is a bit boo- just discovered my scanner doesn't work in Windows 7 & phone pics of bits of paper are always dubious!

Existing

• oldbutnotdead
• 20 Jan 2015
• 1

Proposed

• oldbutnotdead
• 20 Jan 2015
• 1

Above existing doorway

• oldbutnotdead
• 19 Jan 2015
• 1

LH purlin support

• oldbutnotdead
• 19 Jan 2015
• 1

RH purlin

• oldbutnotdead
• 19 Jan 2015
• 1

RH 2

• oldbutnotdead
• 19 Jan 2015
• 1

Plans amended to show bannister rail

 

[ree]

So you intend to move the bathroom door/wall forward 600mm?

You also intend to move both bedroom door openings 600mm towards the RH purlin?

Quite what you intend for the purlins i dont follow. Whatever, work on the purlin "propping" first, before moving anything else.

Remember that Acrows or Strongboys need to prop off sole plates across the first floor joists.

Why not put a level on the purlins to see if they have sagged? Do the same with the loft joists.

What section are the loft joists and what dimension are they spanning?

 

[oldbutnotdead]

Morning chap- ta for reply. Yes you've summed it up quite nicely there.
Purlins- all I want to do with them is make sure they stay where they are! Regarding propping them I'll be propping the floor below as well (joists run front to back in the bedroom floors) as well as using spreaders (scaffold planks).

My main query is am I better off replacing that cracked lump of masonry above the existing bedroom door (and the shoddy looking brickwork that the purlins are sitting on) as part of the job (installing lintels and moving doorways) or should I just needle the wall (as well as propping the purlins) and titivate as normal?

Purlins are level above the bathroom/landing and a bit droopy (like the rest of the building) in the RH bedroom (room where the pictures were taken)- the far end wall is about 50mm lower than it should be, all happened a long time ago.

Joists in the bedroom ceiling are very skinny things- the largest is 100 x 50 spanning 3200. But they are 200 years old so somewhat stronger than modern timber. A couple have rotted (due to leaking roof valley- now fixed- ) so will be replaced with 150 x 50 (as per TRADA tables)

 

[maltaron]

Your proposed drawing shows the right hand door tight against the top of the stairs. Building regulations require I believe a 600mm gap between the top of the stairs and the bedroom door.

 

[oldbutnotdead]

Ta for tip about the staircase- the caption is misleading, the staircase rises the other way (so that line is in fact a bannister rail round the landing rather than the top step). BCO has had a look at the scheme & is happy with the overall concept of moving doorways etc- he's also remarkably comfortable with cracks in old buildings

 

[ree]

You indicate that the bathroom walls are "half brick" - are these walls going in 1/2 brick down to the foundation?
Are the stairwell walls also in 1/2 brick all the way from top plate to bottom foundation?

Do the purlins sit in party wall or gable wall brick pockets?

Without knowing the above info its difficult advising you about propping the purlins.

AAMOI: if you have any thoughts about future floor developements in the loft, now is the time to slide up some appropriate lengths of joisting or floor panels.

 

[oldbutnotdead]

Afternoon ree. Yes those walls are halfbrick to what passes for foundations...

As is the wall at the side of the staircase

Purlins are about 10 metrrs long, pocketed into brick st eithet end (gable ends, not party walls) and joined/supported by chunky timber trusses at 3500 from each gable as well as these halfbrick walls.

So i reckoned there wouldn't be much load from purlin to halfbrick wall and i was right. Half turn on acro with minimal effort lifted each sife by the millimetre i needef.

Predictably the brick plinths are v unstablr without load so they're getting teplaced.

Pics lstet and apologies for spelling-phonr and my fat fingers are not getting on.

Spelling etc now corrected. But can't upload video boo- I'll have to do some stills tomorrow.

 

[oldbutnotdead]

UPDATE
Purlins are sat on acro props. Brick plinths that were supporting the purlins had a right wobble on them without load so they came down. The top course of the cracked parallelogram of masonry came off really easily- the rest of the chunk took some hammer action but it's all gone now along with the door skin, old wooden lintel and lath and plaster existing cloakroom front wall.

Tomorrow's job- acquire a 1200mm lintel, cut RH side out, brick/block LH side to give me 800mm opening, top opening with lintel, build up to support joists and purlins. Not all in one go of course. Hope it isn't too frosty tonight.

 

[ree]

Perhaps if you posted pics at each stage it would supply general interest, and show and give DIY'ers some info about propping?

 

[oldbutnotdead]

Fair enough.

RH purlin

• oldbutnotdead
• 20 Jan 2015
• 1

LH purlin

• oldbutnotdead
• 20 Jan 2015
• 1

Pics showing the acros supporting the purlins (I made the V blocks out of gash bits of 3 x 2- not compulsory but they do reduce the chance of the prop slipping from under the purlin. Blocks are screwed to the prop through the standard holes. There are metre long bits of 4 x 2 under the acro bases running across the joists- and downstairs there are acros underneath these acros with spreaders (more 4 x 2) across the joists in the ceiling and between the bases and the floor

Door wedge

• oldbutnotdead
• 20 Jan 2015
• 1

Never seen such monsters

Door wedge 2

• oldbutnotdead
• 20 Jan 2015
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And another

Check out the size on these wooden blocks (that the doorskin was spiked to). Not much risk of that frame rattling loose

Doorway sans cracked lump

• oldbutnotdead
• 20 Jan 2015
• 1

So far so good

Raggy LH edge

• oldbutnotdead
• 20 Jan 2015
• 1

Typical- the edge I have to build onto is all over the place

Nice RH edge

• oldbutnotdead
• 20 Jan 2015
• 1

While the one that is getting cut out is beautiful.

And views of the doorhole and what was behind the doorskin- typical the face I have to block to is random and the face that's getting cut back is lovely. Means I'll be using bricks rather than blocks on the lefthand edge- be able to tooth them in as well as put frame cramps in.

 

[oldbutnotdead]

And here are the wobbly purlin plinths (if this link works)

https://www.dropbox.com/s/v6ecwk3o2ios1mb/VIDEO0014.3gp?dl=0

oops!

 

[ree]

I'm wondering what happened next?