Filling Gaps in Stone Mullions

[PhilOldChurch]

Hi all,

I'm interested in what type of mortar / filler I should be using to fill the gaps around these Stone Mullions (see attached pic)



Some of the other window mullions round the place (Converted Church) are painted but I don't necessarily want to just fill & paint over. In any case I will need to use the correct product. I've found http://www.lime-mortars.co.uk/lime-mortar/hydraulic/NHL3.5/10kg on the web. Could this be what I should use?, also I could fill various other gaps around the house, for example in the stone flooring if it's the correct stuff.

Thanks very much, in advance for any advice you may be able to offer.

 

[Gareth Hughes]

Just bumping this up as new members' posts take a while to appear and tend to drift down the page.

 

[88v8]

Hello and welcome.

Yes, that sort of lime mortar stuff. Well done! Not being funny, but already you have leapt to the top of the class in not reaching for a bag of cement.

There may be more local suppliers.
Ty Mawr for example, where you can also learn much about the care of old stone buildings,
https://www.lime.org.uk/catalogsearch/result/?q=Lime+mortar+mix
Mike Wye
https://www.mikewye.co.uk/product-category/lime-products/

Edit your profile to show your location, it may help give you local recommendations.

If the gaps are more visible to the passing eye, you may wish to match the stone colour. Your local stonemason will probably sell stone dust. Do you have an odd bit of stone kicking around in the churchyard? Take it along, see what he thinks of the colour.
In that case I would use one third NHL 3.5
One third stone dust
One third aggregate. The aggregate will depend on the size of the gap. If it's thin, then silver sand which you can get at a garden centre - it's sharp but fine. If the gap is larger, then a more generalised local sharp sand.
As a rule of thumb, use the largest aggregate that will go into the gap. The aggregate must always be sharp, never use soft sand with lime.

If you just want to fill the gaps and aren't bothered about matching the colour, omit the stone dust and use 1/3 lime/aggregate, or a commercial mix.

The stone needs to be slightly damp before you start. A hand mister is good. Press the mortar in well, tamp it hard with a suitably sized piece of wood. This will minimise shrinkage. When you finish, rub off any stray mortar with a piece of old sacking. Over the next three days, damp it with the mister. If the window is south facing do the job in the winter or shade it from the hot sun. If shrinkage cracks develop after the first day, just mist the mortar again and batter it vigorously with a churn brush to consolidate it. Shrinkage cracks are more likely if your mix was too wet.
https://www.mikewye.co.uk/product/churn-brush/

An old church, eh? Don't see many of those on here. Look forward to seeing more of you, perhaps.

Ivor

 

[PhilOldChurch]

Thanks very much, Ivor.

I've tried to update my profile but cannot seem to get to that page (within my profile), I'll keep trying though. I'm in Chesterfield. The property is a Grade 2 listed Church (converted into a residential dwelling). Built 1849.

I'll have to sand down the mullions a little before I start as they have been covered with some kind of varnish or sealant which has run and looks awful. I'll take pictures and post when I do this job.

There are lots of interesting features in the Church, including an organ that still works, stained glass windows, marble plaque in the Chancel etc. The organ will be restored by an expert. I've only been here a couple of months but am slowly working away on smaller jobs myself such as fitting a Cast Iron air brick where only a gap existed before. All of these will be replaced in time (the others are standard modern house type air bricks) when I have the whole place pointed up and damaged stone replaced.

Thanks again.

Phil

 

[88v8]

xI've tried to update my profile but cannot seem to get to that page ... an organ that still works

Profile… your username on the top rh.
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Have seen some church conversions with horrible modern windows and overall looking pretty bleak. Sounds as if you found something better.
Do you play?

Ivor