Chimney in a state

Discussion in 'Builders' Talk' started by radus135, Sep 25, 2017.

  1. radus135

    radus135 New Member

    Hi folks,
    Looking for some help and advice if anyone can spare it .
    We moved in to our new house relatively recently and have noticed some water ingress to a couple of the rooms.
    I went up on the roof yesterday and found,
    trees growing in a valley, broken ridge tiles, slates, pointing from skew stones missing and
    one of the chimneys is in a pretty poor state causing me major concerns.

    The pointing is knackered and sections of the chimney stack are severely loose with some fallen away already.

    I've been frantically looking online to remedy this asap I've found that the use of cement based mortar on sandstone is a no no and lime and sharp sand sounds like the way to go.

    I picked up a couple of sacks of hydrated lime and sharp this morning but need some more advice..

    Is this the correct lime to use and what should i mix? I was going to go 3-1

    Secondly, can I use this mortar for sticking the loose sections back on or should I use cement mortar for this with lime pointing.

    Thirdly, I have read that the lime needs to cure in good weather conditions..around 7 days..living in the north east of Scotland in September this is going to be a tall order. Is there anything I can do to speed up the process or is there anyway to help protect it from the rain?

    Any advice would be appreciated as I am stressing out because we have a 2 year old and (due to being injured at my previous job) have no spare cash at the moment to have this professionally repaired. I can turn my hand to a lot of things but this is something new so thought it better to ask the pros for advice before firing in.

    Cheers


    Trying to upload photos but it's not letting me..
     
    Last edited: Sep 25, 2017
  2. stuart44

    stuart44 Screwfix Select

    I would use a hydraulic lime, either 3.5 or 5.0 rather than the normal hydrated lime which is normally used in cement mortar. Plastic sheets protect from rain, hessian for sun or frost protection. When mixing up you might find 50/50 sharp/building sand easier to build with. 20 minutes in the mixer/leave for 20 to fatten up/couple more to mix again. Not too much water to start with.
     
  3. radus135

    radus135 New Member

    IMG_5254.PNG IMG_5253.PNG
     
  4. radus135

    radus135 New Member


    Thanks for your reply

    Ok. think I'll go back to the merchants tomorrow and swap the hydrated sacks for hydraulic and get some builders sand to go 50/50 with the sharp. Might sound daft but when you say to leave it 20 mins to fatten after the being in the mixer 20 mins do you mean just turn the mixer off and let it sit then turn it back on and add more water if needed for the next couple mins?

    3-1 mix you reckon?
     
  5. stuart44

    stuart44 Screwfix Select

    If you have rented an electric mixer it's easy to switch off for 20 minutes and then back on again.
    3/1 is the standard lime mix, although some experts have said that years ago hot lime was used on site which expanded and made the mix closer to 1.5/1.
     
  6. radus135

    radus135 New Member

    Thanks again for taking the time to reply.

    Neighbour has a mixer he is going to lend me for as long as it takes.

    Got 3.5 lime now and going to go ahead with the 50/50 mix of sharp and builders sand like you said.

    Im not sure how I'm going to repair the big chunk that's come away from the left side. The stone is more like a facing or a slab -maybe 50mm thick and want to replace this (if I can) and point.


    Any ideas?
     
  7. stuart44

    stuart44 Screwfix Select

    Are you looking to replace the stone or just repair it?
    For some of the repointing the joints are so thin I doubt if sharp sand mortar will go in them, so you may need a lime putty mix.
     
  8. radus135

    radus135 New Member

    Thanks again for the reply stuart

    I'd love to be able to fully replace the stone but at the moment it's just not possible.
    I discovered that what I thought was some sort of facing was actually about a quarter thick piece from the block presumably due to water getting inside the stone and being unable to escape has forced it out.

    If I can just repair it so it's sound over the winter months then I'll get onto rebuilding properly in the spring/summer.

    You're right, the joints are really thin in places - I'm
    trying to track down a merchants in the area that stock lime putty - surprisingly not common where I live even though there are a heap of sandstone buildings..

    I went ahead and mixed up a small
    amount of the 3.5 hydraulic lime up by hand today to see what I'm dealing with. I properly measured 3-1 (rather than shovelling it) and it turned out pretty dry and not that easy to work with. I've used it on my sheds sills to see how it goes anyway.

    From the photo my big concern is the gap in the middle. If I just pointed in and around the crevice to stop water getting do you reckon would that be enough? I don't have any pieces of the chimney to stick back in (I suspect it fell out before we bought the house and was disposed of)
    ..Obviously I can't chuck in half a bucket of mortar in but just want it watertight
     
  9. stuart44

    stuart44 Screwfix Select

    You could build the gap in a bit with some small bits of stone and use some red dye in the mortar and fill in the gap. Then cut out enough to make a smaller joint.
    This would help get you through the winter. Maybe a repair to the fillets and the flaunching.
     

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