Rotten rafter ends

[Anonymous]

We have recently bought a listed farm workers cottage. It is about 200 years old with 1929 modifications.

I have just discovered that there is a roof leak (presumably dating back months or years) which has rotted a foot or more at the bottom ends of three rafters. Two of the rafters are up against stone walls, so I can only get at one side. I assume the rotten ends need to be removed and new timber spliced in. I'm a pretty competent DIYer. Is this the sort of thing I should attempt, and if so, what is the best way of doing it? It goes without saying that the leak must be traced and fixed too!

I would be very grateful for any advice anyone can offer. I can post a photo if this would help.

Many thanks

Roland

 

[Anonymous]

Not quite sure what you are up against, but always go for the simplest solution. It sounds as if you could just cut out the rotten section and then form a bolted sandwitch witj two new rafter feet. I hope I don't need to tell you to provide adequate support in the meantime! Mike.

 

[Anonymous]

Hi Mike

Many thanks for your reply. I would be grateful if you could help with another question.

What is the best way to support the rafter before I cut the end off? Is the load vertical or perpendicular to the rafter? If so, I assume I should put a prop under it at the appropriate angle. Or is the load along the length? If this is the case, I'm not sure how to do it.

Is there a book or a web site you could recommend that gives details of this kind of thing? I expect it would also be useful to other readers of this group.

Thanks again

Roland

 

[Anonymous]

Post a photo if you have one Roland, it would help.

Bryan

 

[Anonymous]

Hi Bryan

Here's a photo with the rotten rafters arrowed. You can probably see the dark areas anyway.

Any suggestions would be gratefully received.

Roland

 

[Anonymous]

Is this the bottom of a valley? I can't make out what the diagonal is in the centre. I wouldn't give any specific advise because, without being on site, it is almost impossible to assess. However it looks like you will have to attack this one from the outside, remove some stonework and make the whole thing accessible. Doing the repairs will probably be quite simple - it's getting at it that is a pain. God I hate doing repairs like that! Mike.

 

[Anonymous]

Just thought of something else that might help. There is a wonderful little book called The Roofing Ready Reckoner by Ralph Goss. If you want to get your head around roofs and be able to build one this little book is a gem.
To boost your confidence get a copy of the book and some tile batten and you can scale down what is in the book and build mini roofs! Anyone with even a passing interest in carpentry should get a lot out of this. Mike.

 

[Anonymous]

You are right that it is at the bottom of a valley. This explains the diagonal rafter in the centre at right angles to the other two. The leak is probably in the leadwork in the valley as there is some old stick-on flashing there which has probably failed.

The diagonal in the centre is the one that is most difficult to get at as it very close to the wall at the back. I think attacking it from the outside by removing stonework is a non-starter, as the wall is about 3 feet thick and it is at the intersection with an attached barn.

Is it a normal practice to repair a rafter by butting the new section to the cut end of the old one and bolting through it with steel plates on either side? I think there would be room to do this. If so, where can you buy the necessary hardware? Or can you bolt it top/bottom instead? Might this actually be stronger?

I was also wondering about how best to support the rafters while doing the job. Supporting it vertically is quite easy, but is there also a load pushing along the length of the rafter? If so, how do you support that?

I understand that it is not easy to give advice when you can't actually see the site, but having never done a job like this before I'm just trying to understand what is usual practice.

Thanks once again for your help, I certainly appreciate it.

 

[Anonymous]

It looks to me as if the rafter feet are bedded into the wall. If this is the case then you will HAVE to take out some stone.
It looks like you will have to be carpenter, plumber, stone mason and roofer to do this job! Don't take this the wrong way but I doubt you have anything approaching enough knowledge to tackle this on your own.
You really need someone with a good all round knowledge of building and the skills to go with it.
Post up your location and perhaps somebody will be able to recomend a local guy. You do the labouring and learn from the tradesman. Most guys are only too willing to show you how things are done if you approach them in the right way. Supply plenty of tea and fairy cakes and be prepared to be the but of lots of jokes. Mike.

 

[Anonymous]

Hi Mike

Sorry I didn't reply sooner, but I've been a little busy.

Thank you for your advice. I don't take offence at your comment, but I'm not sure on what basis you conclude that I have insufficient knowledge. I have some experience (albeit self-taught) in all the trades you mention, including plumbing, though you must have fundamentally misunderstood the job if you think any plumbing is involved. Also this is not a job that requires any significant labouring, so your final suggestion probably isn't that viable.

I was hoping to get some specific advice about techniques (e.g. how to support the rafters/joists while replacing the rotten sections) but I didn't get it. Maybe it's too much to expect anyone worth their salt to give their time and experience for free.

Are there really any good builders who will give away their hard-earned knowledge in exchange for tea and cakes? I really hope so, but I doubt that the business is like that any more, if it ever was. My location is Stirling, so if anyone wants to give me an estimate for the job (with or without teaching me) I would be very grateful. Tea and cakes will be provided unconditionally!!

Regards

Roland

 

[Anonymous]

I think Mike means a little Knowledge is dangerous.
Especally when it comes to supporting a structure.
If you support it wrong......well no need to tell you what might happen
The plumber could be about the dressing or fabricating of the lead.

***but I didn't get it. Maybe it's too much to expect anyone worth their salt to give their time and experience for free.***

That is bollocks and you Know it.
Mike, me, and many others are only to please to tell anyone, how to do anything' part with any Knowlodge, etc.
But there are some things that you just can't explain through a few pics and on a forum.
Use your common sense man!!!!!!
Regards
FUMMING!!!!!

 

[Anonymous]

Hi Jake

I'm very sorry if I offended you or any of the other people who generously give their time to help people who ask questions here.

I also understand that it far from easy to give detailed advice in a few words and when you know only an outline of the problem. Maybe you and others know your salt, but it's very difficult to demonstrate it in a simple message and it would take too much of your valuable time to give a fully detailed reply to every question.

Perhaps what I was trying to say (rather clumsily) is that if you want detailed technical advice then maybe this is not the place to come. However, if you want general advice about a strategy then it can be very useful. I simply misjudged what I could expect. Maybe I also got the wrong impression from the first reply to my query.

On the other hand, how about telling me how you supported the rafter last time you replaced a rotted end? Maybe it doesn’t apply to my situation, but it would be interesting to read anyway.

 

[Anonymous]

And I'm sorry for that outburst, but it's not me you should say sorry too....... it's Mike.
Anyhow post some more pics, futher back, with some elevation on them.
As I said if you support it in the wrong place It would be dangerous and you could do more damage.
If none of us can help you perhaps you should try and get a local builder in to look.
He maybe able to assess it better 'in the flesh' so to speak.
Please don't be put off okay ;o)
keep posting

 

[Anonymous]

Sorry Mike!!!!

It's not possible at present to get a photo from any other position. The access is very limited, primarily due to there being a loft conversion (the photo was taken through a removed section of plasterboard at the back of a built-in wardrobe) and a partition to the right allowing Velux windows to illuminate the ground floor below.

We both understand it's not possible for me to give you every detail, so..... can you tell me what method you used to support the rafter last time you did a similar job? I'm going to use timber props below to support the joist.

 

[Anonymous]

Would it be possible to get a builder or structural expert in, paid, to advise you?

 

[Anonymous]

Of course, but I'm hoping to get suggestions from more than one place before I decide what to do, this forum being one of them.

Do you have any direct experience yourself? If so, I would be very interested to hear your suggestions.

 

[Anonymous]

As Schoolmarm said best get someone in...
It's impossible for me to judge from the pics you sent in.
Go down to your local hostilary and ask if theres a local builder or carpenter about. Ask him/them if they/he can have a quick look.
Lace his hand with some silver
I'm 99.9% sure he'll look and advise you.
Just tell him you want to do the job, but your not sure how to support the rafters.

 

[Anonymous]

It is difficult enough to work out the best way to do these sort of jobs when you are on site! Via the internet it is virtually impossible. Also it would be irresponsible for anyone to give specific advise on this without being able to see the job. Mike.

 

[Anonymous]

Thanks for replying and for not taking offence at my comments. I fully understand that it is difficult to offer specific advice through a discussion forum, and that things could go wrong following any such advice because the advisor didn't have sufficient information (or the worker didn’t have sufficient knowledge or skill).

Having said all that, let's simplify things and completely ignore my specific situation. What method did you use to support the rafter of a basic single pitched roof last time you replaced a rotten end?

 

[Anonymous]

#51 has done a lot of this type of restoration on his house, he may come on and offer advice.

I'm not sure if that advice would be relevant though.

I have no experience. When we were worried how to support a wall and strengthen it we got a structural person in who did a quick sketch.

I would be worried in your case that to get correct support you would have to have an acro long enough to go through to ground floor.

Unless you could insert one of those strong boy things which sort of cantilevers off walls etc. But that brings you back to access, thick walls etc.