Cracking, swollen render - please advise

iamparakeet

Please see the below job and photos posted to MyBuilder.
I would like some advice on breaking exterior wall render, and especially a swollen part (final pic).
What is the cause, what is the fix, what category of tradesperson is appropriate and what should I expect to pay?
Thank-you very much.

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We moved in to a Victorian terraced house in July 2013. The house had received an extensive renovation prior to sale. On our request, the seller also made remedial works to a defective damp-proof course at the rear kitchen.

Quickly, we found the interior kitchen wall plaster cracking at three walls, including two walls where the damp-proof course was replaced, one of which has also bulged so as to dislodge a skirting tile...





As of today, late January, outside inspection reveals damage to the renovators' new rear render at the back and site-return of the property. This cracking is occurring above two sets of double patio doors (one rear, one side) and above the side-return rectangular kitchen window...





Of particular concern, a higher part of the wall above the rear patio door has swelled and cracked...



I am concerned about water damage.

I am seeking competitive quotes with a view to carrying out this work in the next month or two:
1. Repair and re-render the exterior walls, bringing them to such standard to afford best protection against the elements and making good the work to be visually consistent with remaining render.
2. Replace cracking interior kitchen wall plaster, making good so as to be smooth and properly attaching the loose skirting tile.
3. Advise on any further required work to protect property against elements.

Please advise if plasterer is not the appropriate trade.

NB. Damp inspection in autumn showed no interior dampness signs by professional using a detector device.

maggiecon

Hi,

I am not an expert by any means but it doesnt look like damp to me, more like movement. Is this a new extension to the property or did the previous owner just install new patio doors.

warmhands.coldheart

robertandrews wrote: »

......... On our request, the seller also made remedial works to a defective damp-proof course at the rear kitchen........

If you look at any website with regards to fitting/injecting a new damp proof course into a wall they pretty much all recommend you remove all plasterwork after up to approx. 1.2m ~ 1.5m above the DPC, and renew it... to do with salts etc accumulated in the plaster. when DPC is injected basically plaster can fall away as it dries out..

was new plastering undertaken after the DPC was rectified??

Leon_W

Looks like movement to me as well. Why is the architrave around the door in pic one split ? Water wouldn't do that !

SG27

Do you know what was done during the renovation? It's quite common to get some cracking after major work like extensions or loft conversions etc. although they do look like quite severe so could be other causes?

Did you get all the building regs sign off for the work when buying?

iamparakeet

maggiecon wrote: »

I am not an expert by any means
but it doesnt look like damp to me, more like movement. Is this a new extension to the property or did the previous owner just install new patio doors.

Not an extension, a renovation which removed the rear-room chimney breast to create an extended kitchen. Amongst other work, two double patio doors were added - one at left, one at rear.

warmhands.coldheart wrote: »

was new plastering undertaken after the DPC was rectified??

New chemical DPC was injected, then - apparently by same damp professionals - walls were re-rendered with two coats sand & cement inc water proofer, and then walls replastered.

Leon_W wrote: »

Looks like movement to me as well. Why is the architrave around the door in pic one split ? Water wouldn't do that !

Indeed. Looking back at a photo I took during house inspection in April 2013, there was no sign of the architrave crack, nor plaster cracks... I wonder if the plaster expanding has put pressure on the architrave...

SG27 wrote: »

Do you know what was done during the renovation? It's quite common to get some cracking after major work like extensions or loft conversions etc. although they do look like quite severe so could be other causes? Did you get all the building regs sign off for the work when buying?

What regs do you think I should have expected? I have Building Regs/certification for chimney breast removal, electrics and central heating installation, plus guarantees for first and second DPC injection. Nothing on work beyond chimney breast removal, external render etc.

--

To give you all a better understanding, I'd like to show you all a couple of room plans, and then survey excerpts and a log I have been keeping of the issue. First, you see the extended kitchen with utility and WC to the rear. I have marked some previous work and current condition...





2012/2013
House refurbished:

• Inc DPC w/ Permagard Guarantee Bond.
• Inc removal of chimney breast - Certificate of Completion, Building Regulations, local authority

May 2013:
Home Buyer Report: (excerpts)

• DPC, E4: “No apparent barrier from dampness passing from the ground…”
• Damp, E4: “There is some internal dampness at the base of the walls caused by a lack of an adequate DPC. You should have (inspection and remedy).” Mortgage requirement per Lender’s Valuation Report: “Remedy dampness.”
• Cracked exterior render, E4: “External rear faces of the wall are covered with a coating of cement and render. The render has some cracking but there are also some areas of hollowness where the render is not fully firmly fixed to the brickwork, and repair is needed..” Mortgage requirement per Lender’s Valuation Report: “Repair cracked/broken render.”
• Wall movement, E4: “The walls have some sign of movement in the past but this is not structurally significant. A range of factors common to properties of this type and age can cause the outside walls of a dwelling to move by small amounts.” Comment per Lender’s Valuation Report: “The property has suffered some minor movement in the past but not recent, serious or likely progressive.”
• Wall plasterboard defects?, E4: “The outside walls have, at least in part, a dry lined plasterboard internal surface and this may be hiding damage or defects.”

May 16, 2013:
Independent damp inspection:

• Found: “Moisture readings taken using a Protimeter Surveymaster moisture meter indicated some dampness in the apparent newly plastered walls of the rear kitchen and adjacent utility/toilet at ground floor level. The wallplaster appeared to be cracking/shrinking in a few areas.”
• “Exterior DPC injection holes may have been plastered over?”
• WC: problems at all three walls.

May 31 & Jun, 2013:
Remedy: By another damp company:

• Plaster hacked off: Kitchen rear wall, right wall, utility/WC
• New chemical DPC injected, re-rendered walls (two coats sand & cement inc water proofer), then replastered walls.
• New 30-year guarantee issued to developer.

Jul, 2013:
Moved in, observations since:

• Interior observations as listed in original post, cracks developed soon.

Autumn 2013
Summer/autumn 2013:

• New damp professional, using meter, found no indication of dampness.
• He advised let settle, then patch using Polyfilla.
• But cracks have worsened and hallway door architrave has cracked.

Winter 2014:
Exterior crack observations

• Exterior render cracks and swollen individual part only recently became apparent following recent rains.

I hope that helps you kind souls help me. Thank-you.

SG27

What regs do you think I should have expected? I have Building Regs/certification for chimney breast removal, electrics and central heating installation, plus guarantees for first and second DPC injection. Nothing on work beyond chimney breast removal, external render etc.

Sounds like you have the required documentation. Sorry I can't help more with the source of the problem.

iamparakeet

An update for all…

We have had three builders (but no structural surveyors) out to assess and quote.

Each says the cause/s are:
- Shoddy/cowboy exterior rendering job - sprayed-on tyrolean poor, covering underlying wall cement cracks. Water penetrating wall.
- Poor or hasty internal plastering and painting during refurbishment and/or following remedial damp-proofing.
- Possibly some movement, but nothing significant.

They all suggest hacking off exterior render back to the brick, then replastering and respraying, to ensure no more water can penetrate from outside.
Then, after some weeks, to replaster internally-affected areas.

Cracks are worsening or new cracks appearing every day, it seems. It's quite upsetting. Since the original post, the wall is cracking in the WC, behind the kitchen radiator and even in the middle room at the wall that is not externally-facing but which is shared by wall hosting the musty, damp-affected kitchen cupboard…

On which point - having removed the kitchen unit kickboard to inspect the hidden side-return wall (internal) during builder assessments… it is an absolute mess. Masonary at the base of the wall with the floor has crumbled away due to damp. The builders probably did not damp-proof this wall, and/or there was a history of damp.

We are assessing builders' quotes:
- Builder 1: External Parex 2-coat coloured render, flat finish @ £2,925, rough finish @ £3,275
- Builder 2: External scratch coat, top coat, tyrolean finish with drips and beads; internal replastering @ £5,800 + VAT total
- Builder 3: External base coast, scratch coat; rough finish @ £2,250, smooth finish @ £2,550 (no VAT); all with lime additive, drips and beads.

We are also now considering reappointing a damp-and-timber contractor at same time to shore up the defences whilst the plaster is off.

Calling our insurer to check the position alarmed me since they warned me about the negative impact of an assessor finding evidence of subsidence (none of the builders believe there to be). We believe insurance on storm damage grounds to be a non-starter since, whilst the worst of the damage has been exacerbated by the recent rain, the cause is thought to be workmanship.

I am also not convinced about our current damp-proof course guarantees, which were made out to the seller.

Our original surveyor who carried out the Home Buyer's Report will not come back out and has advised appointing independent damp & timber specialist who is a member of the PCA.

If anyone here still thinks I should get a structural surveyor to investigate to possibility of movement/subsidence, do please say. Some hairline cracks are evidence up and over two parallel kitchen walls from where a wall was removed.

Thanks.

cyclonebri1

Render doesn't swell, and it doesn't expand, well at least not to the extent your pic shows.

Radsteral

before you invite any more , either yourself if you can or if you cant get a labour , give him a hammer and a chisel and remove all cracked plaster but dont throw away keep each bag of rubble where they were taken
once the brick is revealed , if the brick got cracks then its more likely movement.. if the brick doesnt have cracks then some thing to do with the plasterer
if the plaster is red colour it means it should not have been used in ground floor , its gypsum based, draws moisture = a bit of water and its had it
if the plaster is dark, means is sand and cement and the muppets who did it di throw in quite a lot of cement which can make it crack prety bad


outside render its pretty bad aswell

SG27

I would be concerned about the amount of cracks that are appearing. Maybe a structural engineer might be a good idea just to rule out structural problems? You don't want to spend thousands on repair work only to find the problem isn't fixed.