Timber Frame Dwelling in Ireland

[roneill]

Hello,
I am an engineer curently working in Ireland. I am looking for advice on timber frame constructed dwelling and what to look out for at the various stages of construction. Is there any so called common problems. I have also heard that the life span of timber frame constructed house is 60 years!! what happens after the 60 years?!! Should there be or is there a process after a this number of years that the life span can be extended.
Your comments and help will be much appriciated.
Regards

 

[civilperson]

Where did you hear that the lifespan of timber frame constructed houses is 60 years? I grew up in and my parents live in a timber framed house built in 1888. I have seen churches and barns timber framed in Pennsylvania from the eighteenth century (still in daily use). Termites and dry rot can affect wood at any age but with those factors controlled I do not know of age effects that limit the usefulness.

 

[roneill]

The 60 year life span is a requirement set out in the British Standards 7543:1992. I am concerned about dwellings that are built in compliance with this current requirement. I want to know what possible problems or what actions are to be taken after the 60 year life expectancy of the timber frame. You must also know that the outer leave is of a standard block construction. The timber frame is the inner leave, with an air cavity seperating the two. You must also remember that the climate is moist the majority of the time in Ireland.

 

[RockEngineer]

The Timber framers guild is one of the premier organizations for information about Timber Framing in the United States.

http://www.tfguild.org/pubpg.html

Their "Timber frame Joinery and Design Workbook" is very informative about problems you can come across when designing Timber Frame structures especially designs that cause high tension joints and how to avoid them. Their web page has lots of helpful information. Their tour of Timber frames in Britain in Sept could be of interest to you. I know there are also European Timber Frame Guilds.

 

[looksatstars]

Common problems for timber frames come from bad joinery such as tenons that have broken due to the stress of drying. Another problems is the connection of the posts to the foundations, always a difficult connection of wood to concrete but a gasket and hurricane strap work well.
Another problem is tradesman cutting thru the timbers for their work which is a no-no.
I would also doubt that 60 years even in moist conditions. The outside of the timber can get wet as long as it has air circulation. An 8"x8" timber is a big piece of wood.
I designed timber frame homes for 5 years and hardly a single problem structually as everything is over designed.

 

[Ron]

It sounds as though you might be reading something into the standard that is not there. I believe the 60 years would refer to a "minimum" not a "maximum", though I'm not familiar with British Standards.

Here in the US, 60 years is not a long time at all for wood or timber structures as others have noted. For true timber framing, the old methods work quite well.

 

[pba]

There are of course cruck barns and similar buildings in the UK and Ireland which are hundreds of years old...

I think Ron is correct the 60 years is in effect the design life of the building. Nothing catastrophic happens after 60 years - in reality the opposite is likely to be true - 60 years should demonstrate that the building is sound and normal maintenance is then likely to yield an indefinite life.

As to potential problems with timber frames try the following organisations:

BRE (Building Research Establishment) - They produced some good 'Defect Action Sheets' and reports of timber frame defects.

TRADA (Timber Research and Development Association?) - Used to produce good simple guides.

COFI (Council of Forest industries)
Nordic Timber Council

These are all UK based organisations but Ireland is not really different (and not significantly wetter).

Timber frame is a well documented subject in the UK as the house-builders of the 1970's merrily created large numbers of properties whithout regard to correct design or detail and this has subsequently needed research to verify their durability and safety.

 

[Ussuri]

As a side note, BS 7543:1992 has been replaced by BS 7543:2003.