Tiled roof over thatch (under thatched) new project

[Peppercorn]

We have just purchased and started on an attached property next to our renovated Stone built cottage, it is another Cottage of similar construction although smaller. I will have many questions over time but my first is for information relating to the roof. Does anyone have experience of this tiling over thatch, the pitfalls, I intend to remove it to see the full extent of any beam or roof strut damage, then to put insulation into the property ( probably celotex like). Any feedback greatfully received and hello to all of you out there in cyberspace.

We have flagstones and inglenook fireplace with bread oven etc to be uncovered, what a project, I feel really privileged to have the opportunity to preserve this property.

 

[worms]

Sounds like an interesting project and welcome to the Forum. I can't help on this query but just bumping this back up, since first time posts can take a while to appear and risk getting lost down the page.

 

[DJH]

The only thing I can tell you Peppercorn with any certainty about removing old thatch is that it's a filthy old business. You will end up with an enormous heap even from a small roof. I had a small corrugated tin roof over the thatch of what I believe to be the original dwelling with probably hundreds of years of straw over it. The original pine wood structure was eaten away by woodworm and it was just the ceiling holding that part of the roof in place.

If it's at all possible leave the ceilings in place and put plenty of dust sheets or plastic over the contents of the rooms below where you are removing the thatch. The dust and debris will go everywhere! In my experience when another roof is put over a thatched roof the rafters for the new roof will rise above the thatch giving a steeper pitch. If this is ion good condition then I would suggest leaving it there, clear away the thatch, insulate and cover the roof over with the original tiles or slates, assuming you haven't broken too many taking them off in the first place.

Good luck with it

Doug

PS I expect the original thatchers would have used most if not all of the tools on page 13 of the Whatsits topic :wink:

 

[tobydog]

Peppercorn - welcome to the forum. Whilst I am not a thatcher, I am the owner of a thatched cottage.

I have never seen a case where someone has tiled over the underside of a thatched roof. Are the tiles simply attached to laths on the rafters and then lime plastered or are they physically attached to the thatch? It seems odd if someone didn't just lath and plaster which is the case with most houses (thatch included) where you have vaulted ceilings (except ours unfortunately which is gypsum board ).

The only hard old coating I have seen directly onto thatch is where sometimes the underside is lime rendered between the rafters in loft spaces. This can keep the wind and occasional leaks on old thatch out without overaly impacting the thatch's ability to breath. I'm not sure it's very common though.

Is your house listed? If so, you may want to get in touch with your local Conservation Officer before you start ripping things off. Even if it isn't listed, you may want to consider leaving it in place if it is repairable and isn't causing damage to the thatch or structure of the house. It's all part of the character although I have to say it isn't the prettiest bit of work I've seen. If it's 'recent' work then replacing with lath and lime plaster could look much better.

More photos would be good once you uncovered a part of it for inspection.

 

[DJH]

I thought Pepercorn had tiling over thatch? :?

( Quote Does anyone have experience of this tiling over thatch, the pitfalls, I intend to remove it to see the full extent of any beam or roof strut damage, then to put insulation into the property ( probably celotex like).

Found this in amongst our thatch when we took it off.



Doug

 

[tobydog]

Doug - I read it as you initially until I looked at the picture properly. You can just make out what look like tiles through the plaster.

Maybe your finding was an offering to the God of Thatching for a long and effective life. I know there is a God of Lime Plastering who Zebra worships.

 

[DJH]

Oh yes, I see what you mean Toby. Until you pointed that out I couldn't really make head nor tail out of the picture. It's certainly very unusual in my experience to have thatch over tiles. Very odd I think. :? :?

 

[Jellyfire]

Never come across tiles over or under thatch either, but like Tobydog we own a thatch. Afraid I'm no help on the tiles, but as you mentioned celotex, in my experience our thatch is about as good an insulator as you could hope for. We have a very deep (1metre approx) covering so maybe that's unusual, but it's far more effective than any insulation boards would be, so not sure if adding insulation to the roof would really be worth the time and money. Maybe others with less depth may say differently though

 

[tobydog]

We have 12" of reed which is no where near as good as a metre of straw. Our gable ends are also just lath and plaster only so rather cold. I'm just finishing off the insulation so that we have a cold loft space rather than a warm one. Celotex under the thatch between the rafters shouldn't be a problem so long as you leave an air gap between the Celotax and the thatch. There may be issues with how you retro fit a vapour barrier with the thatch already in place but that's a question for someone else.

 

[Jellyfire]

Ah ok, that would make sense. In which case insulate away then! Our roof is toasty warm, it's just the doors, windows, chimneys and walls we get draughts through!

 

[DJH]

I've found a few pictures of my 'tin over thatch' roof.

 

[Peppercorn]

Thank you all for even taking notice of my post and poor photo. I am currently un bricking the wood burning oven / fire and then will be opening up the Inglenook, which is about 3meters wide with bread oven (cast iron door) visible so far. Excited and scared are words that come to mind!! bit by bit and the jigsaw will come together! Regarding the thatch, we have double romans on the outside, thatch under, then plastered on top (internally), possibly lath and plastered, but haven't explored fully yet, although the story is that just post war when they were building the shiny new council houses the resident lady of this property put her broom through the thatch saying that she would have to be priority now!! This would be about the time of this thatch getting "a roof" maybe, I'm expecting dirt and lots of it, but hoping the "newly" (more recently) laid roof and timbers are in good condition, well better condition than the original Aframes visible through it............

 

[88v8]

Hello and welcome.

Can't really make out much from that photo, but if the underplastering is original then I would not remove it. Perhaps strip the upper layers of thatch, but leave the bottom course if it's in decent nick, which is what thatchers usually do anyway. If the roof is not sagging then don't worry about the rafters, they've been there a long time and will probably outlast us all.

Indeed if it does appear to be sagging, bear in mind that it might have been like that from new. Straight timber was a luxury item which many builders could not afford.
Bear in mind that if you take the roof off, and the building is not listed, there is a danger of Building Control getting involved and insisting on all sorts of 'strengthening' measures which will destroy the charm and history.

We have all original underplastering here in two upper rooms, and some of it is indeed pretty rough, but it's original.
One can only destroy originality once.

As to insulation, I would never destroy original features for the sake of saving a bit of heat. As has been said, thatch is a superb insulator.

DJH, lovely pegged rafters in that last pic. They look rather like the hazel rafters in our roof, which I am sure are all original from 1620. Ours are pretty wormy and a couple in the attic space had to be doubled-up as they had sagged. I used a length of wonky hazel trunk from our garden. Fortunately in the attic there was no underplastering to consider. I would never put modern straight beams in an old roof, not so long as we still have hazel in the English countryside. I was a bit surprised to find hazel up there, I must admit, I had vaguely assumed it would be elm as with the main frame. I guess. as I said, they only used straight timber where it was needed.

Ivor

 

[DJH]

Yes they are Ivor, lovely pegged rafters. I saved as many as I could and it broke my heart to take it off but it was beyond repair. As you can see there's only a fraction of straw left after they pulled it down from underneath to put up a new ceiling about 120 years ago. This was evident because there was no heather visible which there should have been as it was used as a first coat before the straw went on. This is the only part of the house externally where I haven't replaced like for like, in fact if I did,I would be putting corrugated iron sheets back up.



Surprisingly the pegs were of oak which is a rarity in Ireland. I saved as much as I could to go with other things I found, to keep as evidence of what work I've done on the house.

This is the roof shortly after now covered with natural slate. Although there is strong evidence to suggest both from the construction and materials used that this was the original dwelling, it is now subservient to the larger house which was built onto it subsequently. As a nod to originality and after my surprise when removing the clay hips and ridges and from the main roof and finding that they were made by Sealey Bros from Bridgwater (about 15 miles from home in England) I sourced some to put on the new roof. My understanding is that tiles,bricks and ridges like this which came from the clay pits surrounding Bridgwater were shipped into Waterford,New Ross and Cork as ballast before returning with timber and other goodies.
This picture was taken before they were put on. Ignore the Sky dish :roll: . That is due to be mounted out of sight one day.