1930s roof - how soon will I need to replace?

[Question]

I have a 1930s house (with an extension built twenty years ago), and it has the original roof.    Can I assume the roof will last another 20 or 30 years, or could it need replacing much sooner? 

 

I ask as we may end up living here for the rest of our lives, and if it would be much cheaper to replace the roof now, given inflation, rather than in  5 or 10 years time.    (We are trying to plan everything now.) 

 

Grateful for any advice. 

[markc]

Morning, there are many buildings out there with roofs 100’s of years old so it’s difficult to put a timeline on things. When you look at what a roof has to endure you start to appreciate why some fail sooner than others.

wind, rain, snow, orientation, pitch, airborne salt, sand etc. moss … if moss gets hold around slates they soon start to crumble.

any photos so we can give you an idea of condition?

[Marvin]

It also depends on the quality of the materials and installation to start with.

[Question]

Thanks very much for your reply.  Here is a photo. 

[ToughButterCup]

6 hours ago, Question said:

...

Grateful for any advice. 

 

Get a properly qualified opinion - from a structural engineer who has no personal interest in the outcome of the survey.  Do your Due Diligence thoroughly . Research engineers who have roof specialists / experience in roof surveys , find three, ask for a fee proposal from each, and an example of the kind of report they are prepared to submit for the price they charge.

If work needs doing ask the SE for a specification of that work, and submit the spec. to the builder. That process, though a bit 'heavy' will potentially save you money: reduced chance of specification creep by the builder.

 

You need evidence that the work needs to be done: photos / video / reports (dry rot for example) / dampness measures.

 

"There's a bitta' rot 'mert, in't right-'and corner, oop top."     isn't good enough. Cheap, though. At the time. Not so later.

 

PS, the taller of the two chimneys needs a bit of work: a bit of rendering's come off.

Scaff > strip back > re-render > strike scaff > clear up.

Roof could be inspected at the same time : if difficult, get a teenager with a drone to video it.

Edited December 23, 2022 by ToughButterCup

[Marvin]

Hi @Question The first thing I would look at is the chimney stacks.

 

Its very difficult to decide such a thing. 30 years is a long time. I know that we didn't like the idea of replacing it in 10 years time. However we planned to install PV panels on the roof so didn't want to do it after that.

 

We had the same decision when we bought our bungalow. I looked at the other properties around and noticed problems with mortar coming out of ridge tiles joints etc, and the roofing felt in ours was not so good especially over the soffit so we ended up replacing the lot. 

 

I felt happier using dry verge and dry ridge systems which avoided relying on mortar.

But as @ToughButterCup says a proper independent inspection is best.

 

 

[Gow]

6 hours ago, Question said:

I have a 1930s house (with an extension) 

I have a 1930s house too with a slate roof. The house was built by a reputable builder in 1939 to be exact. Occasionally, due to high winds, a slate or two will need replaced. Fortunately there is a local roofer who does the repairs and his bill is always reasonable. One of his other customer, my nextdoor neighbours, had their slate roof replace during summer this year. I asked him if I should consider replacing mine. He thought it would be a waste of money in my life time because the durability of a slate roof should be about 100 years. I'm already a golden oldie therefore I feel sure that I will be pushing up daisies long before the slate roof here needs replace!

[Redbeard]

I take it they are clay tiles? It may be just my eyes but they look wider than 'standard' Rosemarys. I did a porch roof with 1920's clay Rosemarys which had been stripped off an replaced with concrete tiles, which probably won't look as good in 20 years as these looked after 90 (when I used them). Equally I have seen some clay tiles very badly spalled after far less time. My slate roof is 120+ years old, and one I was looking at earlier this week 150+. Both have had a lot of care and maintenance, and I would be pleasantly surprised if a clay-tiled roof lasted as long. But follow the others - close inspection and opinion on more than just the tiles, too.

[Question]

Thanks I love the advice about getting the right structural engineer to give an opinion, and getting evidence.   They can look at the chimney stack as well. Thanks @ToughButterCup and everyone else!

 

Tomorrow I'll take some photos in the attic of the inside of the roof, and of some tiles close up. It is a start. I'll post them here.