Can I still use my Hydraulic Lime?

[Tom]

Hi guys

A couple of months ago I bought a whole load of bags of Hydraulic Lime. The builder, in his wisdom, left them in the yard uncovered. Not long after we had all the rain and all he covered them with was a 1 ton sand bag. Of course, this has leaked and the lime along the edges of the bags has gone hard. Because of this, he threw it all in the skip....about 3 bags worth!! Anyway, I've told him I can't afford to throw things away like this and I've taken all the hard blocks back out of the skip and stored them under cover. Can this lime still be used? I'm guessing it can, since I know that mortar can be knocked up again, but how can it be used in the mixer to make mortar? My builder says if we break it up into smaller bits we'll still have lumps in it that won't mix with the sand well enough. Can we soak it in water in a dustbin and add it to the mixer, with the sand, as a 'wet' product? Will there be any detrimental effects? Thanks.

Jaqy

 

[biffvernon]

Whooaa! I wouldn't use it for building motorway bridges or airport runways. The 'hydraulic' part will have reacted with water, rather like ordinary cement, and it doesn't work twice. The non-hydraulic part will, at least in part, have carbonated, and that won't happen twice either. I would use it in the mix for non-critical applications but regard most of it as part of the aggregate fration of the mortar and so use fresh lime as well.

 

[MdB]

I agree with Biff.

Hydrated lime can be stored dry or stored wet in the form of putty. Once it dries again though carbonation occurs and then can't be reused.

Hydraulic lime can only be stored dry as it starts to set once wet the same as cement though I believe this takes longer to occur.

Put the bags back in the skip..

 

[skier-hughes]

Unless you need to make some limecrete I'm with the others. I used some old bags to make up the base for my greenhouse, taking at about 50% good lime and 50% not as my calculation for how much I was using, and adding another 50% good lime to make up.

It set and is nice and hard now.

 

[biffvernon]

Put the bags back in the skip..

Even if you don't use it for building, it will be fine as a fertilizer for the garden. Don't skip it!

 

[MdB]

Put the bags back in the skip..

Even if you don't use it for building, it will be fine as a fertilizer for the garden. Don't skip it!

Gardening... Now there is a subject I know little about (apart from growing nettles, I'm an expert at that). I do know that some plants hate lime so be careful on exactly which ones you fertilise. Lawns do like it though I think which is where I empty my bucket when I rinse it out.

 

[Tom]

Thanks everyone for your replies. I'll hang onto it and use it when we come to put the stone flags down outside. I just can't stand to see waste, especially when the equation is 'someone else + my money' !!!

Thanks again

Jaqy

 

[Anne]

You can use it as long as you mix it with lime that didn't get damp just to be sure I wouldn't use more then 1/4 of the damp stuff to 3/4 not damp in the lime part of your mix, in fact it does a great job making the mortar look older as you get those big white lumps in the mortar that we all see in our houses. They probably couldn't store lime in as dry of conditions as we do today and the lumps were simply what happened. We had this happen on a bag and I've since intentional done this to copy the original.

 

[Tom]

Anne, thanks for this. I've changed my mind and will now use it for the mortar in my garden wall. I actually like the white lumps in old mortar, so this will be great for me Thanks again.

Jaqy

 

[skier-hughes]

I thought they used to make it on site as they needed it, so didn't have storage problems. Our mortar has big lumps of stone etc in, but I've not seen anything that looks like lime.

Graham

 

[MdB]

Our old lime mortar has big lumps of lime in it. I believe I read somewhere that this is quite common due to the way it was made locally.