wood embedded in wall

[MetManMark]

All
We have had dry rot issues (as discussed elsewhere on this forum) and we are trying to get everything ready for the dry rot experts that are coming to treat everything. As part of this we have removed a lot of the plaster and wood that is within spitting distance of where rot has appeared. The house (built in 1777) appears to have 2 courses of bricks starting from the floor and then a piece of wood that is the same sort of size as the course of bricks - then more bricks and then another 'course' of wood at waist height - more bricks and then another course of wood at head and then more bricks (apologies for the poor description but hopefully you will get the drift). We have had to remove some of the timber that was at waist and head height as it had been attacked by the rot. These we replaced by brick (original) and lime mortar. We are thinking what to do about the timber that we have removed at skirting board level. Currently we have wedged in some brick just to stop the bricks above from falling. We are thinking that timber replacement isn't a great idea and that we would replace with bricks & lime mortar. However, our (trusted) builder has suggested that we put in some sort of membrane - presumably a sort of damp course. Is this wise? I was thinking that just replacing with lime & brick would do the trick - I understand that putting in damp course membranes isn't a good idea in older properties that were designed not to have one.
Thoughts please!
Thanks
Mark

 

[Keithj]

Is the house listed? That will make a difference to what you can do (although not so much, possibly, to what you should do).

From the description, a damp proof course is probably not the best idea around.

I would be inclined to get an expert along to have a look and advise. Devon is well supplied with people who know about these things - I'm sure someone will be along in a minute who can suggest a suitable firm. Treating the rot is certainly a safe first step, but after that I'd want expert input.

 

[plasticpigeon]

Was he wood in the wall for wainscotting? Did the room have panelling before? How about just making the conditions so that the rot can't survive? Treatment is not always necessary apparently.

 

[MetManMark]

Hi there
There wasn't any evidence of panelling. I was told that it could have been either (a) to enable an easy fixing for skirting / dado rail / picture rail or (b) to ensure that the brickwork was level as the house was being built. Both of these suggestions sound plausible but not massively convincing... The problem is some of the wood is completely rotten and crumbles to the touch. Whilst we are conscious that we want to make it as dry as possible (we are putting in a French drain and have dug out the concrete floor to reinstate the suspended floor) we do need to do something about fixing up where the wood has rotted.
Cheers
Mark

 

[AMc]

I would definitely seek expert, in person advice about installing a plastic damp course. It might be a very wise thing to do, but it might also be a massive mistake. It's hard to say without more expertise!

I had similar wood strips at similar levels in an upstairs Victorian extension. It had been used to support upright battens which in turn had been used to support laths for plastering. I suspect it was to provide a set of level "ring beams" around the room that allowed the plaster support to be fixed perfectly plumb. It may also have helped to tie the walls together while the original lime mortar set during construction.
We did something similar to batten the room for insulated plasterboard using plastic wall plugs where there wasn't wood. Some of the wood had rotted and was simply replaced with spare bricks. There was no significant damp problem though. In your boat I would probably use brick at the lower level.

 

[dandrew]

If what you have is a strip of softwood that runs around the whole perimeter it sounds like a 'ground' which was nailed to wood 'plugs' hammered into mortar joints between bricks. The ground was used to nail skirting to and the top of it was usually bevelled (sloping downwards towards the wall) for a key for the plaster, and as you'd imaging they guide the plasterer as to the finished plaster thickness. The upper timber might have been another ground for nailing a dado rail to. You definitely have grounds if they are nailed at intervals to wooden plugs in mortar joints and stand proud of the brickwork. Occasionally wooden bricks are built into door or window jambs as fixing points for frames/sashes etc. but these are intermittent and would not typically run along the whole perimeter of a room.

The plug which is wedge-shaped was our forefathers version of the rawlplug and was hammered into the space left when the vertical mortar joint was chopped out between 2 bricks using a plugging chisel.

David

 

[MetManMark]

OK - thanks for that. Any suggestion regarding whether it is OK to replace directly with brick or to put in some sort of damp proof?
Cheers
Mark

 

[middi]

First. If your house is 1777 build out of " soft" bricks it must be remembered the this is the height of the era when brick houses were overtaking the more traditional and conventionally timber framed houses. All these houses( brick) were invariably built out of soft bricks and lime mortar.
There a number of reasons why " strips" of wood were inserted within these walls in the single or double brick elevation. Apart from the obvious reason for hanging floors, pots, pans or coats etc.. The main reason was in the mistaken belief that due to slow setting and fragility of the mortar during the early stages of construction, the inserted wood would aid to their present and future stability of walls and acted as a binding strap. They were right of course, exept that they didnt account for the fact that when the wood rotted it would have nad the opposite effect ( or more likely they didn't care, as they would be dead). I don't think building regs were in force then and it was a case of the blind following the blind. ( allowing for the benefit of heindsight of course)

Second. It is not strictly true that dpc/dpm cannot be fitted to period buildings that were not originally provided with such " system".
At times it becomes nenessary ( and to the building benefit, with CO blessing of course) that these " modern aids are used to further safeguard and prolong the building useful life. What cannot be done( in the majority of cases) is to use DPM,s without inserting DPC.s and lapped onto each other. DPC can be used without the need to use DPM but not the other way around. This obviously depends on individual assesment of circumstance.
Middi.

 

[MetManMark]

Thanks for your posting, Middi. I should have said that the external walls are a mix of stone (ground floor) and brick (first floor). The walls that I am referring to are all internal walls made from a single thickness of 'soft' bricks. These are typically of two sizes but they aren't very regular so I guess this was before they were really mass produced. Anyway I have to confess that I don't follow your comments about DPM and DPC. I thought that the 'membrane' was the material used in a damp proof course? Personally I am starting to think that just replacing with the same bricks (we have some in the garden for some reason) and lime mortar will be sufficient.
Don't get me started on CO & Building regs people. The house was previously rented by the council and we are discovering lots of stuff that we would never have done.... (concrete floors laid, breeze block walls put in, fireplaces bricked up, plasterboard everywhere, bitumen paint on the walls in an attempt to tank an area)

Mark

 

[middi]

It would be only in extreme cases when these old buildings need drastic action of DPC or DPM inserted, usually in cases where the house is built on a bad drainage site and the walls are prone to act in a capillary manner to suck water from the ground making their lower section damp. usually refered to as " rising damp". if the outer stone skin and the inner brick skin are well pointed with the correct mortar, the exterior level is lower than the internal floor level and rain water drain system in good condion, normally, there should be no problem.

To clarify.
DPM ( damp proof membrane) is used to isolate the floor area from any damp that is likely to perculate from under the building into ground floor room space

DPC ( damp proof course) is a means to stop water being " sucked" up the walls from the foundations.

If DPM is used where there is a bad damp siruation in a floor area without -ALSO- inserting a DPC, there is an increased risk that all the damp under the membrane will find it's way into the footing walls and make these damp.

A DPC (this can consist of modern impermeable pastic based felts, fired or stone tiles etc..) is inserted in walls approx 150mm above exterior ground level and can be used in old buildings that suffer from (drastic) wall damp problems. Can be used with or without DPM if rquired.

In normal situations where there is a breatheable floor system as frequently encountered in older buildings, there is no use for a DPM.
Also where there is a suspended and ventilated wooden floor there is no real need for DPM. The only place where DPM is really effective is when used where solid floors are required and -LAPPED- into the DPC, used to good effect with floor thermal insulation. DPM lapped into DPC will create what is effectively complete isolation of building coming into contact with ground moisture.

Middi

 

[MetManMark]

Thanks Middi - all the walls I am talking about here are internal walls. Having dug out one floor that had been concreted over the ground is noticeably drier. As a result I think I'll just put bricks back in place.
Mark

 

[MatthewC]

Mark

My house is from about 1840 and I also found various bits of wood in the walls. One internal wall has a length of something like 4 x 2 at the base (and hence a bit rotten in places) with the rest above being brick up to the ceiling, then stud, lath and plaster upstairs. It has been suggested to me that this bit of wood at the base was there to spread the load of the brick as, without any foundation, a brick wall could settle and hence crack and eventually collapse. If that was indeed the reason, I have to say that it worked. (I don't think that this use was exactly the same as what Middi said, but if it is then I apologise for duplication.)

Other bits of wood were shorter and were used for example to attach wooden corner fittings to the wall. If they were rotted then I have replaced them with wood (if I needed to attach the same fitting) or with brick or stone (as appropriate), using lime mortar.

I would strongly support all those who said don't add a DPC, without very careful consideration.

Don't get me started on CO & Building regs people. The house was previously rented by the council and we are discovering lots of stuff that we would never have done.... (concrete floors laid, breeze block walls put in, fireplaces bricked up, plasterboard everywhere, bitumen paint on the walls in an attempt to tank an area)

Is your house listed? If so, aren't the council at risk of having to restore things to the standard as in the listing details? Isn't that what they would do to us if we did those things without permission?

Matthew

 

[Zebra]

Having dug out one floor that had been concreted over the ground is noticeably drier. As a result I think I'll just put bricks back in place.
Mark

That sounds like the best plan, at least in the short term. You can still continue to assess the damp as you go along, and decide on the best course of action.
I could add that I have gone to the immense and laborious task of inserting a damp proof course lapped into a damp proof membrane in the old part of my house, which is only four brick walls, and around 4m x 3m, so quite small. This was exactly following the instructions that middi gave as above. However, this was only after pretty much exhausting all the other options, ie lowering external ground levels, building a retaining wall to keep the external soil away, repointing in lime, replastering in lime, and removing the internal concrete floor, and where observation over time showed that there was still a problem. It's definately not one to be undertaken lightly!

 

[Mikeyboy7]

All
We have had dry rot issues (as discussed elsewhere on this forum) and we are trying to get everything ready for the dry rot experts that are coming to treat everything. As part of this we have removed a lot of the plaster and wood that is within spitting distance of where rot has appeared. The house (built in 1777) appears to have 2 courses of bricks starting from the floor and then a piece of wood that is the same sort of size as the course of bricks - then more bricks and then another 'course' of wood at waist height - more bricks and then another course of wood at head and then more bricks (apologies for the poor description but hopefully you will get the drift). We have had to remove some of the timber that was at waist and head height as it had been attacked by the rot. These we replaced by brick (original) and lime mortar. We are thinking what to do about the timber that we have removed at skirting board level. Currently we have wedged in some brick just to stop the bricks above from falling. We are thinking that timber replacement isn't a great idea and that we would replace with bricks & lime mortar. However, our (trusted) builder has suggested that we put in some sort of membrane - presumably a sort of damp course. Is this wise? I was thinking that just replacing with lime & brick would do the trick - I understand that putting in damp course membranes isn't a good idea in older properties that were designed not to have one.
Thoughts please!
Thanks
Mark

Hi mark , I have the same problem here ,
What did you do In The end
Thanks Mike

 

[Cubist]

Hi there and welcome,

There was a practice among some builders to install timbers at the, crudely, foot, waist and head height of a brick wall for use as 'nailers' for skirting, dado rails, picture rails and wall mounted cabinets of one sort or another. It was thought to be a good idea as some of the plaster mouldings of the times were quite heavy and included a wooden sub-structure of their own - these would be screwed to the wall and the holes filled with a little plaster of Paris.

A good idea maybe until the timber embedded in the brickwork rotted out. When that happens its best to replace the timber with suitable bricks.

Cheers,
Cubist

 

[malcolm]

Here's a photo from my kitchen halfway through replacing a rotten bond timber with bricks. The rest weren't rotten so stayed in place. Mine was a 9 inch wall so didn't need supporting. Not that the timber had been offering any support in the first place as it was far gone.

It's worth also sorting out the thing that caused the wood to rot in the first place. Normally impermeable coatings like cement or plastic paint on the outside or gutter leaks are responsible for this sort of thing.

 

[Mikeyboy7]

Hi there and welcome,

There was a practice among some builders to install timbers at the, crudely, foot, waist and head height of a brick wall for use as 'nailers' for skirting, dado rails, picture rails and wall mounted cabinets of one sort or another. It was thought to be a good idea as some of the plaster mouldings of the times were quite heavy and included a wooden sub-structure of their own - these would be screwed to the wall and the holes filled with a little plaster of Paris.

A good idea maybe until the timber embedded in the brickwork rotted out. When that happens its best to replace the timber with suitable bricks.

Cheers,
Cubist

Thanks cubist

 

[Mikeyboy7]

Hi there and welcome,

There was a practice among some builders to install timbers at the, crudely, foot, waist and head height of a brick wall for use as 'nailers' for skirting, dado rails, picture rails and wall mounted cabinets of one sort or another. It was thought to be a good idea as some of the plaster mouldings of the times were quite heavy and included a wooden sub-structure of their own - these would be screwed to the wall and the holes filled with a little plaster of Paris.

A good idea maybe until the timber embedded in the brickwork rotted out. When that happens its best to replace the timber with suitable bricks.

Cheers,
Cubist

Hi cubist ,

I’m in the process of restoring a 1900 house and I’ve come across a few problems. My floors are a mix of concrete & suspended timber ,

Floors are dug up now for 4 months .

Q1 I am considering putting in glass insulation with LimeCrete is it worth the expense & the effort (100sqm) should I do concrete or some sort of hybrid floors .



(My worry with concrete is, the problem below will only get worse .

my internal walls are timber stud , infilled with red brick , problem is timber at base 4”x2 but has narrow in places , it’s wet , soft & rotten in places

Q2 can I cut out sections and fill in with red bricks with lime

Or should I replace with timber ?

Thanks Mike

 

[Mikeyboy7]

Hi there and welcome,

There was a practice among some builders to install timbers at the, crudely, foot, waist and head height of a brick wall for use as 'nailers' for skirting, dado rails, picture rails and wall mounted cabinets of one sort or another. It was thought to be a good idea as some of the plaster mouldings of the times were quite heavy and included a wooden sub-structure of their own - these would be screwed to the wall and the holes filled with a little plaster of Paris.

A good idea maybe until the timber embedded in the brickwork rotted out. When that happens its best to replace the timber with suitable bricks.

Cheers,
Cubist

 

[Mikeyboy7]

Here's a photo from my kitchen halfway through replacing a rotten bond timber with bricks. The rest weren't rotten so stayed in place. Mine was a 9 inch wall so didn't need supporting. Not that the timber had been offering any support in the first place as it was far gone.

It's worth also sorting out the thing that caused the wood to rot in the first place. Normally impermeable coatings like cement or plastic paint on the outside or gutter leaks are responsible for this sort of thing.

View attachment 10453

cheers Malcolm, my wall is only 4” thick and the timber 4” & 4” is below the skirting board level , I’ve cut a few bricks and used hotlime , I’ll give it a week or so and see what it’s like