Period - what happened to my wooden lintel? Is it nasty rot?

[FamilyWiggs]

OK - so I've spent the past day or two stripping the dry-lining and polythene tanking out of what was my office to turn into a snug for the kids, and their games consoles.

I've exposed some nice things - the original stone walls and haired lime plaster with many many many layers of limewash. Thankfully all seems nice and dry, except round the windows which I think just need sealing/pointing properly.

When I removed the polythene from under the lintel over the window recess, the beam just fell into splinters on the sill. Assuming when the tanking was done in 1974 the beam was in reasonable condition (unless they were real cowboys and just tanked in a failing lintel), I'm wondering what has caused this collapse and whether I need to be worried. Since they appear to have shoved a load of cement mortar between the beam and the stone above forming a slim concrete lintel, I'm not too worried that the stonework will collapse this weekend instead of any of the past couple of decades.

Further worries - the roof purlins aren't socketed into the end-wall; they were simply resting on the mortar on top of the now disintegrated beam. The span to the end wall from where they are last supported is only about 8 feet, so again I am not hugely concerned immediately, but have propped them anyway. There is some evidence on the purlins of worm holes - but this is only to be expected with new timber (well, 1970s timber) as it dries out.

The other worry is that whilst the visible end of one purlin is solid, the other appears to have disintegrated like the beam - but I'm not sure if this is the remains of an old purlin I can see or the end of the new one.

The final worry is I have what appear to be some dead brown tendrils of something looking like ivy without the leaves - currently encased in polythene on one plaster wall - I'll try and post a pic when I have removed the polythene.

Pics follow, but my questions are:

a) what caused the failure of the original lintel - it is very dry and crumbly. Is it some dreaded kind of rot?

b) will I be OK to put a new lintel in and leave the purlins resting on it. To remove and replace those purlins will be a very major undertaking.

PIC: General view.



PIC: Not much of a lintel any more, is it?



PIC: Close up of disintegrated beam.



Many thanks for any advice.

 

[Jellyfire]

Cat help on the questions Im afraid, but I love that window!

 

[FamilyWiggs]

And the tendrils... rather worried now I can see them. Although they seem to be "spreading" from the edge by the window.

PIC: General shot.




PIC: Close up.



Pic: Even closer.

 

[Penners]

what caused the failure of the original lintel - it is very dry and crumbly. Is it some dreaded kind of rot?

Ubdoubtedly. But I'm afraid I can't help you in identifying it - let's hope that Matt will happen by. My guess is that, at some point, that timber has been very wet for an extended period, but that's far from an expert view.

will I be OK to put a new lintel in and leave the purlins resting on it. To remove and replace those purlins will be a very major undertaking.

I wouldn't consider removing the entire purlins, but I would consider extending them in some way in order to socket them into the gable wall. Could you cut them back to good wood, treat them with a preservative, then scarf some extensions on, or even bolt an overlapping piece of timber on to one side of each purlin?

a snug

Don't you start! I'm having quite enough trouble with Joce in another thread. :evil:

 

[FamilyWiggs]

what caused the failure of the original lintel - it is very dry and crumbly. Is it some dreaded kind of rot?

Ubdoubtedly. But I'm afraid I can't help you in identifying it - let's hope that Matt will happen by. My guess is that, at some point, that timber has been very wet for an extended period, but that's far from an expert view.

Many thanks Penners - I was hoping Matt would happen by. I think I can detect some very fine pale tendrils in some of the wood. I suspect it is nasty rot and the room was very wet at some point hence the tanking. Although other than around the window surrounds, there is no sign of mould or damp in the plaster.

In the absence of an expert, I've done the next best thing (!) and searched google images for wet rot and dry rot pics. I can't see anything that looks like my timber (which I believe is cuboidal cracking). There is very little (if any) frassy/dusty stuff.

I think I'd better take the ceiling down and everything and just go back to the bare walls. Then I can see the pulins better and decide what to do.

Frustratingly all this exploration/demolition to see the wood is preventing me from doing something else interesting - I think I have found some red figures/writing between the layers of limewash... but will need a lot of care to flake it off and investigate.

 

[middi]

Looking at those pictures it is quite obvious that at sometime prior to any " restoration" attempt those beams ( lintels ) had been subjected to a substantial amount of wet and eventual rot. Once these were isolated from the wet, damp and rotting cycles they have dried resulting in "honeycombe" looking pattern and next to useless as structural supports for which they were intended.

The ideal restoration would have been to replace those rotted beams/lintels like for like when the " restoration took place, unfortunately it is too common for builders to " reinforce" the existing weakened structure by adding " stiiffners" to existing beams, mainly due to cost involved.

There is nothing wrong with the " stiffning" approach to weak beams either with wood or steel, and sometime even preferable if it involves a lesser amount of original fabric to be destroyed.
You have to evaluate ( or have someone else to do the evaluation) as to the structual integrity of the repairs as existing by close examination.

Middi

 

[FamilyWiggs]

Middi - grazie mille.

 

[middi]

Prego, prego....., I wish I could be of more help.

Middi

 

[FamilyWiggs]

No - you have been very helpful.

I need to open up further - but I think structurally I will be OK to put in a couple of oak lintels there, possibly extending the purlins too. The room is small and the roof, although slate, is similarly small. The amount of stone work on the inner (unsupported skin) is probably 6 feet wide rising to a point about 3 or 4 feet above that lintel. An oak lintel will be fine for that and the pillars either side deep enough.

I hope.... 8)

 

[robgil]

Did your home belong to spiderman at one time?

 

[Matt Green]

what caused the failure of the original lintel - it is very dry and crumbly. Is it some dreaded kind of rot?

There's no need to dread any kind of rot, only the bills that follow the repair of the water leak that caused it. It's a brown rot, possibly cellar rot (Conoiophora puteana) which usually has olive green/brown hyphae, but it's done a pretty thorough job on the lintel and it might be a tough of your actual dry rot *insert foreboding organ music*. Whatever it was, it sounds like it's long, long dead. Brown rots remove cellulose from wood leaving the lignin behind, which is brown. When the wood dries there's obviously less of it that there once was, the rest having been converted into fungus, so it shrinks and cracks. Quite dead. Nothing to worry about. Engage kettle.

Was there a gutter running along the outside that might have got blocked?

 

[Feltwell]

I can hear FamilyWiggs breathing sighs of relief from here!

On a slight divergence of topic:- this reminded me to order some permethrin to treat my cellar steps, and whilst looking online for that I found the perfect birthday card for Matt:-

http://www.amazon.co.uk/Woodworm-Gr..._12?s=outdoors&ie=UTF8&qid=1334504532&sr=1-12

Mind you, given his occupation I'm not sure the woodworm would wish him happy birthday!

 

[Penners]

Well, that is a little bizarre, but even stranger is the line lower down the page, advertising "Woodworm Clearance Sale"!

I bet that has people all-night queueing... :?

 

[LadyArowana]

Well, that is a little bizarre, but even stranger is the line lower down the page, advertising "Woodworm Clearance Sale"!

I bet that has people all-night queueing... :?

Well they will be most disappointed when they finally get to the front, there were no woodworm for sale, just some cricket bats :twisted:

 

[Penners]

Ah, but I wonder what's lurking inside the cricket bats!

 

[Feltwell]

"Woodworm Clearance Sale"!

I typed "woodworm" into Ebay, expecting to just get lots of woodworm treatment stuff come up - instead, most of what it returned was golf clothing & equipment :?:

Turns out that it's a brand name in golf - and what a very odd name to choose. Still, golfists aren't renowned for their sense of good taste.....



You can get golf bags in "Woodworm" branding. Do you think that when the golfist goes for an iron club they are fine, but when they go for a wood club they just find a pile of frass? :lol:

 

[FamilyWiggs]

what caused the failure of the original lintel - it is very dry and crumbly. Is it some dreaded kind of rot?

There's no need to dread any kind of rot, only the bills that follow the repair of the water leak that caused it. It's a brown rot, possibly cellar rot (Conoiophora puteana) which usually has olive green/brown hyphae, but it's done a pretty thorough job on the lintel and it might be a tough of your actual dry rot *insert foreboding organ music*. Whatever it was, it sounds like it's long, long dead. Brown rots remove cellulose from wood leaving the lignin behind, which is brown. When the wood dries there's obviously less of it that there once was, the rest having been converted into fungus, so it shrinks and cracks. Quite dead. Nothing to worry about. Engage kettle.

Was there a gutter running along the outside that might have got blocked?

Matt - Thanks ever so much, I really appreciate your advice. No idea where the water came from - but the room has been re-roofed and tanked about 35 years ago, so leak may have preceded that. Cowboys obviously just wrapped the sodden beam in plastic and left it.

I think I might have a kit kat with my cup of tea, now.

 

[Matt Green]

On a slight divergence of topic:- this reminded me to order some permethrin to treat my cellar steps, and whilst looking online for that I found the perfect birthday card for Matt:-
http://www.amazon.co.uk/Woodworm-Gr..._12?s=outdoors&ie=UTF8&qid=1334504532&sr=1-12
Mind you, given his occupation I'm not sure the woodworm would wish him happy birthday!

That card is fantastic! My wife manages to find me a valentines day card with a beetle on it every year, she goes to extraordinary lengths to find them. I have ten now, all different.

I'm not sure the beetle would wish me well either. I found an adult in my kitchen this afternoon which is very early; either that or it was reconnoitring the terrain for the inevitable revenge attack. :shock:

 

[Penners]

I think I might have a kit kat with my cup of tea, now.

Steady on, FW! You know what a Kit Kat can lead to...




...another Kit Kat, and another, until eventually you end up overweight, short-sighted, no hair and spending your days sadly bimbling about on some internet forum.

Take it from one who knows.