Repairs on SW faces of 1890s half timber frame building

[NiaH]

We live in an Arts and Crafts half timber framed building built by Walter Cave in 1898 in North Somerset.
The wood is pitch-pine and the infills possibly local material/ stone, however there is lath and plaster on the inside of the gable ends from the attick??.
The outside is in need of repairs and decoration and we want to do this properly. I am a beginner at this sort of thing and if I get someone in to do it I want to know that I am not being sold a pup!!!
I would appreciate the recommendation of an expert in the Bristol area!

I have been on the ladder exposing the damage- photo shows few hours prodding and scraping. There are 1-5mm gaps between the wood and infill in most areas and a few areas where water has infiltrated causing small areas of rot to the bases of the verticals. In particular there is one angled beam to a horizontal (in photo) where there is a 30x15x10cm void where wood has rotted away behind the intact horizontal front beam and I removed the concrete repaired infill. There are quite a number of timber shakes in the horizontals and verticals- several upto 5mm across, from which the filler is coming away.
As for the infills there are numerous defects along their edges which have previously been filled but are coming away- but in general they feel solid, but there are gaps on all 4 edges of almost every one. A small infill above the larger area of rot has been removed- it looks to be a concrete repair.

My questions are
1. Could the minor areas of rotten wood be treated with scraping away to solid wood, applying hardener and resin filling- or is scarfing in a better option (some of these are only about 4cm square) ?
2. What to do with the larger area of rotten wood?- any suggestions as the face is solid- its just the big hole behind.
3. Should I fill the timber shakes with linseed putty (does this come in black?)- I could do this myself- perhaps after a few coats of wood preservative?
4. The wood previously had gloss paint stripped from it 11 years ago, and was last coated with Jotun Demidekk on a Visir primer. Would it make sense to give a few coats of wood preservative, then visir and demidekk again or are there better products?
5. I have read that lime is a good breathable material. Could the infill defects and gaps be repaired and filled with eg Old House Store Conservation filler (lime putty based) even if the base material is stone. Would a limewash then be advisable on the infils (for breathability) rather than white exterior paint?

I will attach a couple of photos (if I can) and thanks for any suggestions. :idea:

 

[Feltwell]

Welcome NiaH - nice to see an Arts & Crafts building on here, we don't see many of them.

I can't help you much with your specific queries but others on here have far more experience of timber frame than I have, and I understand water ingress between infill and frame is a common problem. This post is just to bump you back up the list to where you are more likely to be noticed!

Any chance of some more pictures by the way? I do like Arts & Crafts.

 

[NiaH]

Thanks!
I would love some help soon as I want to sort it out before the weather gets worse!! :lol:
With my own additional research I am thinking of filling gaps in infills with Old house lime-putty mix 'coarse stuff' and then white silicone masonary paint
and filling the shakes with ?? linseed putty if I can then put Jotun demidekk on top, and getting a joiner to user repair-care epoxy to repair the rotten wood.

(the second picture shows the gable end infill with alarm box which looks worryingly loose and is a priority)

 

[middi]

Arts and craft, or " mock tudor" timber frame buildings, as the words imply are a craft and an artistic way to reproduce the pleasant outlook afforded by their earlier oak framed counterpart and the " good examples" deserve merit and conservation for future historians.
Unfortunately the timber used for these buildings, whilst of excellent quality, cannot be compared to the longevity or rot resistance of oak. Pitch pine longevity is about a fifth the life of oak when used in exterior situation,then, only if kept well protected with a good coat of impermeable paints.
When originally erected these " pitch" pine structures would have been protected with lead based paints and/or black tar based products as these, whilst not very human friendly, were excellent protection against rot and decay. Unfortunately rot ( mainly due to lack of maintenance) will eventually set in, especially in exposed situation, and once in softwood ( or pine) structures it will create havoc with the timber molecular structure. Once moisture has gained entry at some " weak" unprotected point it will travel within the timber " heart" with no possibility of escape due to the rest of the timber beig covered by paints etc.
There are no short cuts if effective repairs need to be carried out, all rotten timber needs to be removed and replaced and at the same time well protected with presevatives and/or paints or stains. Shakes and splits ( and as long as the timber is sound) can be filled with hard resins and then well protected with paint ( or the more modern protective stains) but it would only be of limited life.
As to the gaps between infill panels and wood, these need to be infilled in order to stop excessive rain gaining entry and settling on the sole plate and at the bottom of the vertical studs end grain, as this is the area where most of the rot occurs. This problem is synonimous with exposed oak timber frame but excessively so with " mock" or softwood frame, especially with the latter, regular maintenance is the order of the day.
As to what would be most suitable to infill these panels to wood gaps, lime putty is easy to apply and smoothed over with your finger, if you want a fast job exterior quality caulk applied with a gun is extremely fast and can be painted over ( that is cheating
You may want to consider ( if room is available ) to repair and treat with preservatives the existing facade and then completely protected from the weather by erecting a " duplicated" facade with new pine timber, stains and contemporary infill and easily replaced panels. Done correctly nobody would tell the difference and the original structure would be totally protected and insulated from the weather

Middi

 

[NiaH]

Thank you Middi,
The house is listed (so I am not sure the CO would allow a duplicate facade) - and we want to do things properly. It looked OK until I went up the ladder with a bradle and started poking and scraping....then I took the pictures.... Some of the areas of rot are due to the design with the base of water tracking beams being affected as you correctly point out. Is resin filling definately a no-no?, this is what a carpenter has suggested as the best current method! I was not convinced.

When you suggest 'impermeable 'paint, does this mean I should steer away from the idea of a breathable stain like Jotun Demidekk, or should I apply coats of preservative such as cuprinol 5* before demidekk? Or perhaps copious cuprinol to the susceptible areas.

Would caulk to the infill gaps allow movement of the wood and water to escape if it did ingress and would it last?, that is why I had thought of the lime-putty mix. I don't suppose lime putty can come in a gun to aid application? Any experience with the oldHouse store lime-putty mix 'corse stuff'? Any type of caulk in particular?- it does sound much easier (and cheaper), but is it the best solution?

For the shakes/ wood gaps, would linseed putty be friendlier and more long lasting than hard resin? Especially for gaps (as in photo) between horizontals and verticals which are quite substantial. My reading suggest it is just for window frames, but some places suggest its use for wood repairs- I am a bit confused :? . On our timbers I can see some brown oily filling which seems to holding quite well compared to the previous resin fillings which are easy to poke and dislodge, so for these larger gaps with good wood I was considering using it.- it seems very flexible to me. Does linseed putty come in black?

Sorry to be asking such basic questions, but I am yet to find a local expert who I have confidence in.

Nia

 

[middi]

Linseed oil putty can be used to fill small gaps an shakes in wood, also a "black" linseed oil can be purchased that can be added to the standard putty (as usually purchased to repair glass in window frames). This putty will allow for a small amount of flexibility that occurs due to temp fluxuations and, ideally, will need a couple of weeks ( or more) after application for the surface layer of the putty to " set" so that it can easily be painted. This is the traditional approach to repair any shakes in pine wood prior to painting. ( most, if not all, Victorian and Edwardian original doors were " repaired" with linseed oil putty after construction to hide blemishes and cavities as these doors were all intended to be over painted) . The reality is that nothing lasts for ever, oil putty will retain flexibility as long as some oil residue remains in the putty mix, this is why good maintenance ( with paints ) is necessary "to trap" oils within the putty and extend their usufull life.

The objective, from your point of view, is to prevent water entering gaps and splits and coatings with impermable paints or stains. I don't think that in your situation " bretheability" of the wood is a concern. The wood is already covered with unpermeable layers of all sorts of paints and fillings and, from a maintenance point of view, maintaining wood "breatheability" is the least of the problems. This is a classic case where modern fillers and stains could be used to extend the life of whatever is left of the existing structure.

If the " shakes" and " splits" were in oak wood then the apprach would be -- " do nothing" if timbers are exposed, Or " stuff sheeps wool soaked with lime putty in the cavities and lime wash over". Using this "breatheable" repair approach with exterior used old pine it will have the opposite effect and will speed up the decay.
If you google " decorators caulk and fillers" you will find an array of modern products that can be used for you to fill the gaps and decorate onto.

Middi