Feasability of DIY re-slate

[kreyszig]

So, having just received a quote for re-laying the slates on our roof (gasp!), I am now thinking about how to reduce the cost of such an enterprise.
At the extreme end of the scale is DIY-ing it. Just wondering if there are any tips/warnings/words of encouragement out there regarding this. I don't have the area of the roof to hand, but it's a good sized 4 bed semi.
I can get scaffolding up to the roof line for gratis which will obviously help a lot, but I would be doing it on my own, with ground level assistance from the boss..

Basically the woodwork is all good, I just want to take off the slates and re-nail the ones I can keep. There are a couple of valleys to redo in new lead (two are already done, not by myself) and re-flashing of three chimneys. My impression is that actually putting the slates down isn't a massively time consuming task?
My current thinking is to tackle a smaller, lower section of roof over the old scullery (single storey you see) as a bit of a test and try to work timings out from there. Any tips on working on a fairly high roof would be well received too! As would strategies for how to divide up the work with respect to time - can I work across the roof in sections or does the whole thing come off and get reslated from the bottom up, for example...

We have a staycation booked for a couple of weeks in September, I'm wondering if this might give me enough time.. also what are people's thoughts on membranes between slate and battens? There's none on ours at present, I wonder if they are much use at all (it's very easy to see any problems with the slates without one). I've seen people talking about adding a layer of ply as well, which makes me think about lack of circulation.

Any and all thoughts and ideas welcome - I realise there's a lot of questions in there!

 

[Owain]

Sarking boards under the slate are standard in Scotland and especially done in wide pine planks give a lovely boarded effect inside the attic

 

[Feltwell]

It would be possible to DIY, but it's a big big job. Personally, given your lack of knowledge and how vital getting it right is, I'd bite the bullet and find a decent roofing firm to do the job IF you really need a complete strip and re-roof.

I had roofers in to re-tile - not slate - my roof when we first bought this house. I worked with them very closely as I was doing a lot of timber and guttering repairs, so saw first hand what they were doing. Without that insight, I don't think I'd want to tackle a main roof. A single storey outhouse, yes I'd have a go at that.

A membrane under slates or tiles in my opinion is a must, go for a modern breathable membrane such as Proctor Roofshield. This can be your only roof covering for a while - the manufacturer says it's good for 3 months as this.

Bear in mind that you'll need building regs approval if you're re-roofing, and that will bring a requirement to bring insulation up to a modern spec.

How much was your quote? And was that for new slates throughout or just replacing the bad ones? Is the roof so bad that you need to re-do it, could you just repair what you've already got for now? Scaffolding is usually a big part of the cost, and is often a reason to replace rather than repair, to avoid the need to put it up again in a couple of years when a few more slates have slipped. If you can get scaffolding for nought then repair may be a more viable option.

 

[kreyszig]

Thanks for the feedback Feltwell. I was quoted £20k to re-use the slates, £17k if I use new slates (that includes new lead everywhere). Might not be too bad for a whole new roof but I just don't have that kind of £.
It's a bit of a snowball affair - my main concern is actually the flashing around the chimneys and the two valleys. If I'm doing those then it seems like I should get the slates re-done too. Perhaps that's where I'm going wrong!
There are already a number of slate hooks in the roof, so I'm working on the assumption that the nails are all about the same age and likely to need replacing.
When the valleys around the gables were done they lost 45% of the slates, so there's quite a high replacement cost in the £20k.

 

[CliffordPope]

It's possible, if you really do your homework, and have a good head for heights.

I slated a one-storey extension, teaching myself how to arrange the battens and get the spacing right by looking at the nail holes in the reclaimed slates I bought. The supplier told me how many I'd need for the given roof area.

I did a reasonable job, a bit wobbly, but nothing like as good as the original on the main roof.
I was ignorant of a few basic facts. For example, slates are not all the same thickness, and you grade them first, so that you lay the thicker ones at the lower slope and gradually they get thinner as you go up. Also the amount of overlap should vary depending on the angle of the roof. Mine didn't really matter as I used underfelt so it wouldn't leak anyway, but it would look wrong to an experienced slater.

If the roof is high, or exposed, you need 1 1/2 width slates at the edges. A cheapskate way is to use half-widths, but they will always be vulnerable to winds.

And so it goes on. I'd do a small roof where it doesn't matter a lot, but never a full house roof.

 

[Flyfisher]

I did most of the re-roofing work on our pantiled house, without any prior experience of such things, so it certainly can be done. The main things I learned were:

1. It's not difficult . . . . if you know what you're doing
2. I couldn't have done it without some experienced help/advice, because I didn't know what I was doing (at first)
3. It takes longer than you expect (and I was working on it full time)
4. Working alone is not very efficient because of all the fetching and carrying involved
5. The sense of satisfaction when finished is immense!

It was not just a re-tiling job because there was quite a lot of repair needed, including rebuilding a dormer (on the rear side of the roof and not shown in the photo below), but even so it was not beyond my average DIY skills - though it took our very own Middi (stand up and take a bow!) who convinced me I could do it and provided the necessary advice and encouragement when needed and when I got stuck he would visit and show me what to do next.

Because of the size of the roof I divided the job into sections, though I tried to make them as large as possible when it came to fitting the breathable membrane. As I got better, the sections got bigger!

Stripped of tiles, structural repairs complete, re-battened and membrane fitted:


Six years ago and showing no signs of any problems since then, the finished roof:



Any tips on working on a fairly high roof would be well received too!

Apart from the obvious advice about being careful (doh!), I found it very useful to make a 'stepping board' from a piece of plywood with battens screwed to the back that would rest on the roof battens. Two of them are just visible in the photo. The plywood should be at least the width of two rafters so it can sit on the roof even when the membrane is in place. Two (or more) of these made it far easier to walk up and down the roof (I found) without balancing on the roof battens and pressing on the membrane.

They also made it easy to sit and rest on occasion . . . though perhaps your ankles and knees are fitter than mine. Spending all day on a roof can be quite a physical strain, especially for days on end! I never felt in any particular danger as, with proper scaffolding, the worst that could happen was slipping down the roof onto the scaffolding, which is pretty unlikely really and didn't even nearly happen. Ascending and descending the ladder was probably the riskiest part of the job. But like any jobs like this where there are potential dangers, it's always good to be slightly nervous about things so that you don't become complacent about the risks.

So, all in all, I enjoy being able to look up and think to myself "I did that" (well, most of it) but I'm also very glad that I'll never have to do it again!

 

[Penners]

Lots of good advice above, and I agree with all of it. Roofing isn't rocket science, provided you do your homework on materials, method and so on. But it is tough work. I don't know what sort of age you are, but the older, the tougher! It's hard on the back, the feet and the knees, and with (nailed) slates unless you're a dead shot every time with the hammer, it can be hard on the thumbs, too! Remember that the steeper the pitch, the more exhausting it will be.

My principal concern would be the fact that you are apparently on something of a deadline for the job. As a novice, the important thing is not to rush - hurry can cause accidents and/or poor work. You need to take your time.

I'd certainly encourage you to go with your plan of trying your hand at a small outhouse roof first.

And yes - you'll be required to lay a membrane under the slates, which is a good thing.

As I'm in a good mood, I will reluctantly forgive you for the word "staycation". :evil:

 

[plasticpigeon]

I've not done any roofing, althought the flashing on my roof is a mess around the chimney and I need to re roof my bay window so I've read a bit. However despite my lack of experience, I think I can quite confidently say that 2 weeks is not enough time if you are on your own. There is bound to be a bit of repair work on some bit of wood or another, and stupid little jobs can sometimes take days. Also do you know how you want to finish the verges, with an undercloak or not? By the way does anyone know how to do the flashing where the ridge of a roof buts up to a chimney stack? Does the ridge tile go over the flashing?

 

[middi]

Some very good advise from other posters. All I can add is this, if you decide to re-lay/replace roof tiles this is the time to think about new battens, new roof membrane, boarding and insulation. Once the roof is stripped for re-working it is a reasonably simple task to carry out the above and guarantee that no more repairs needed for another 100 years or so.

Middi

 

[kreyszig]

Thankyou everyone. I did think 2 weeks was pretty optimistic; but I'm glad to hear that it isn't completely unreasonable to do it on my own (I'm in my late 30s for what its worth). I'm not planning to rush anything - especially if I have a bit of time once the membrane is up.
Flyfisher I think you might have got me with the idea of sense of achievement - it must be wonderful to think you've done that roof on your own.
I think I'll probably see how I get on with the small roof I mentioned and take it from there. And read as much as I can in the meantime!

 

[Flyfisher]

Late 30s? I think I can remember those days, but it was a long time ago. :wink:

Yes, the sense of achievement does tend to help you forget the days when you really didn't want to get back on the roof and the job seems to be stretching out ahead of you and you wonder if it might have been a mistake to take it on at all. But once all the tiles are stripped then you're pretty much committed whether you like it or not, which is where a bit of expert advice and help is invaluable. Also, if you do a half-decent job (which I'm sure you would) then you'll actually have nothing visible to show for all that time and effort anyway! Having a small roof to work on first will be invaluable and should help you make the right decision about the main one.

By the way does anyone know how to do the flashing where the ridge of a roof buts up to a chimney stack? Does the ridge tile go over the flashing?

In our case, the ridge tile went over the flashing as shown in these photos. This is for pantiles of course, I have zero experience of any other types of roof tile.

 

[Penners]

Late 30s? I think I can remember those days, but it was a long time ago.

If you can still remember them, FF, then it's not so very long ago. :wink:

 

[Flyfisher]

:lol: :lol: :lol:

 

[davidbrac]

Not knowing the size of the roof l will add this, you need to make the transition from a stripped roof to a paper covered roof quickly, and you need to be able to finish the slating before the frost comes as some roofing papers loose their waterproofness if the frost gets at them. Also if you are reusing slates you need to practice re-facing them as that was what the difference in cost between new and reused ones.

If the roof size is small and you have the time it would be worth it, but don't forget that there will be repairs to woodwork that needs doing as you uncover it.

 

[Zebra]

I found it very useful to make a 'stepping board' from a piece of plywood with battens screwed to the back that would rest on the roof battens. Two of them are just visible in the photo.

Ah, I see what you mean now. I was imagining one for each foot, attached to your feet, like roof-crampons!

 

[88v8]

I'm roofing my new double garage in reclaimed plain tiles, about 1,100 of them.
Never done before.
My builder was supposed to be doing the job, but he's gone awol.

Echo the comments about it being hard on the (63 yo) legs.
Not bothered about heights, but it's a nuisance when one drops things.

Using stainless screws for the battens, and predrilling the holes so they don't split. Also predrilling the nail holes, not that I'm doing much nailing, just the ridge course and verges.
The new battens are rubbish quality, full of knots.

Membrane - Proctor Roofshield. Good, but beware - it's bright green, don't really want it showing at the gutters.
All-black membrane here
http://www.novia.co.uk/products/bm_bba_breather.html

Hard aligning the second verge. The tile width varies a tad, one arrives at the verge and gadzooks! too wide too narrow, up to an inch out over an 18 ft width, go back and shuffle tiles find wider narrower grrrr.

Wouldn't do a whole house. Hard work, especially slates which are heavy, and don't think I could do it well enough and a badly laid roof will knock the value if one sells.
Hats off to anyone who DIYs a full reroof.

Ivor

 

[plasticpigeon]

Thanks Flyfisher, that looks like a good solution. I can't remember if my flashing goes over or under the slates on my place. I don't think the roofer was particularly skilled so it could be a combination of the two.

 

[CliffordPope]

It looks ugly if you have a continuous piece of lead overlapping the slates. It looks more professional to have a series of lead sections, each one tucked under one slate and then emerging and overlapping the one below.
(A bit like the L-shaped flashing sections you get in a Velux kit)
The same overlap occurs on the face of the chimney breast. The roofer who did my porch made a neat little nick in the edge of each overlapping piece and tucked the tag under the one below to hold it flat against wind.

There are probably a lot of little roofer's tricks and personal trademarks that an expert spots at a glance.
Another is to scratch their name and date on the uppermost piece of lead. There's often a roof's history written up there if you ever get to read it.

 

[Penners]

don't forget that there will be repairs to woodwork that needs doing as you uncover it.

That's a very important point. Pretty well any job that you carry out on a period property will uncover previously unseen problems that add to the complexity, cost and time of the original job.

 

[kreyszig]

Well I've had a word with the roofer who quoted me, most of that price is labour - he reckons it will take 4-5 of them 4 weeks, which puts the scale of it for a one man band in perspective.

As it stands we will focus on getting the known lead problems out of the way first; financially they are in a different league. I'll try my hand at a smaller roof in the meantime. Thanks everyone for your advice; some good knowledge on here and some tips I'll remember. The thought of being able to look up and know I did the roof is going to be in my head for some time.