Float & Set - please help

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Hi,

I’m doing ok with my patching up with bonding, but in a couple of places it is looking like it may need a bit more.
I would like to have a go with the more elegant solution for float & set (rather than D&D) but need some help! :confused:

I found a couple of useful posts e.g. //www.diynot.com/forums/viewtopic.php?t=118896 (useful description from Roughcaster)
//www.diynot.com/forums/viewtopic.php?t=154844 (useful description from Roy C)

When you have a wall that has some surrounding plaster still present it is possible to get a level using a darby, feather edge etc. However, when there is nothing there, how do you do it??? :rolleyes:

The first part I’m struggling with is how do you get the level/depth right?
From a novice’s point of view (in easy words!) I would expect thin wooden battens (prob about 10mm deep) to be nailed horizontally – probably one near the top, one near the bottom and one near the middle to allow a darby/feather edge to be guided across.
Once the plaster has set, they can be removed and you could fill in the gaps. However, I’m not sure if this is right and it may bond to the neighbouring plaster and I’d never get them out! :eek:

Also, I’ve not used a float before - how do you use one?
For example - do you use it after you have passed across with your darby? Do you allow any setting time for your bonding to go off a bit first? Do you wet the float etc? Any tips appreciated!

PS I spotted info from Richard C regarding %age limits of replacing plaster & building regs – thanks for the tip, I will be careful!

Many thanks in advance for any help
 
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how do you get the level/depth right?

just as you said 8mm 10mm battens bottom, middle and just below ceiling you can leave the bottom batten in to fix your skirting to.
remove the battens before the stuff sets.
then simply fill out level.

when the battens are fixed in place use a spirit level and make sure the wall is plumb use packers behind the straps to adjust your levels if need be.
once you have slapped on your bonding or browning (dont forget to pva) and given the wall a pass with your derby or straight edge go back and fill out any voids and give it another pass untill you are happy it is level.

give it time to take up a bit you can then give it a float over, damp down your float and go over wall in sweeping motions of a figure of eight.
you can then remove your top and middle battens and fill out.

depending on room temperature, humidity etc wait till your plaster firms right up and then apply your finishing coat.
 
Hi, I’m doing ok with my patching up with bonding, but in a couple of places it is looking like it may need a bit more.
I would like to have a go with the more elegant solution for float & set (rather than D&D) but need some help! :confused:
Brave man. :LOL:

Hi,
I found a couple of useful posts e.g. //www.diynot.com/forums/viewtopic.php?t=118896 (useful description from Roughcaster)
//www.diynot.com/forums/viewtopic.php?t=154844 (useful description from Roy C)

When you have a wall that has some surrounding plaster still present it is possible to get a level using a darby, feather edge etc. However, when there is nothing there, how do you do it??? :rolleyes:

The first part I’m struggling with is how do you get the level/depth right?
From a novice’s point of view (in easy words!) I would expect thin wooden battens (prob about 10mm deep) to be nailed horizontally – probably one near the top, one near the bottom and one near the middle to allow a darby/feather edge to be guided across.

You’re not far off in fact; you seem to have missed this bit in Roughs description;

Levels for plumb and straight are put on the wall first. These are crucial as you will work from these as you go. They are mostly wooden, and will help to form a screed across the wall from which you will work the straight-edge,and are removed after they are finished with.

Once the plaster has set, they can be removed and you could fill in the gaps. However, I’m not sure if this is right and it may bond to the neighbouring plaster and I’d never get them out! :eek:

Plaster won’t stick to the wood; when you’ve finished & satisfied with the levels, pull the guides off the wall & fill in the gaps & trowel off level with the surrounding.

Hi,
Also, I’ve not used a float before - how do you use one?
For example - do you use it after you have passed across with your darby? Do you allow any setting time for your bonding to go off a bit first? Do you wet the float etc? Any tips appreciated!

I think you’re getting a little confused possibly by the reference to a devil’s float; the base coat is put on between the guides with a trowel. Leveled between the guides with a straight edge & then the guides removed & holes filled; the Derby http://www.screwfix.com/prods/24762...-Darbys/Forge-Steel-Aluminium-Darby-48-1219mm is then used as a sort of large trowel to get a nice flat surface. A little water is used to stop dragging but use only as little as you need to prevent pick up; use too much & you’ll affect the plaster. A devils float is simply a float with some nails banged into it;
http://www.answers.com/topic/devil-float
but you can use a piece of flat wood with nails in or anything that will lightly screatch the surface. You just run it across the base coat to provide scratches in the surface (but not too deep) to give a good key for the finishing plaster.

Hi,
PS I spotted info from Richard C regarding %age limits of replacing plaster & building regs – thanks for the tip, I will be careful!
;)

This Wickes guide (sorry lads :rolleyes: !) may also help as it has some useful pictures
http://www.wickes.co.uk/content/ebiz/wickes/resources/images/gil/20.pdf
 
Bugger should have checked for any replies before posting! :rolleyes:
 
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I always use plaster dabs to bed the battens (dots) into. Once you have the left and right hand "dots" in place and plumbed up, carefully run a length of string between the two, to position any other dots,,,, again, using your straight edge and spirit level to plumb them up..... The position of the dots, depends on the length of your straight-edge, both for vertical and horizontal positions.....

You would use the float "after" the darby.... A well darbied wall or ceiling would require very little work for the float, apart from a light deviling,,, a feather-edge also, can give a similar result,,, it's all in the touch. ;)

Roughcaster.
 
The dots (battens) that I would work from are around 16" to 18" in length. I would place these on the wall vertically, at a height or width that suits the length of my straight edge, (eg, if the s/edge is 6ft 6", I would place the top of each dot a couple of inches below that ), these dots give the screed the desired thickness of plaster. Once I have formed and levelled the plaster screed across the wall, these dots are removed from the wall, even though the plaster screed itself has not set. Once I'm happy with the screed,, and the dots are out, I fill in the gaps where they were, and then start coating the wall "below" the screed right away,,,, time is of the essence...... Once I have covered the main part of the wall, I get my straight edge, give it a wet with a "water :cool: brush" , and then work off of my plaster screed and the "wooden ground" (a batten fixed along the bottom of the wall), using them as guides....... Using a short up and down motion, work the straight edge across the wall. Keep it square to the wall, if you tilt it left or right, it will dig into the plaster...... Once across, fill in/plaster any low spots with the trowel, then go across the wall again, until you're happy the surface is flat. You can now plaster out the top section of wall "above" the screed. Once you think you have enough plaster on the top, using the flat plane of the lower plastered area of wall, carefully run the straight edge across the top part of the wall to remove any excess plaster and fill in any low spots as before, you can level/screed off the top section of a wall with a darby, or a smaller straight edge if you wanted..... Clean the ceiling line/angle off, cut it in, and look along it to make sure it looks straight to the eye,,, clean/cut in and check any vertical internal corner angles too... When the plaster has tightened up a bit, run the darby over it to remove the lines and marks from the straight edge, and generally tidy it up,,,, give it a rub/light scratch with the float when it's ready, then leave it to set up. You can now have a quick cup of tea...... :LOL: but don't be too long, you're ready for the set,,,multi finish.
When you're doing float and set, or rendering, don't overload your wall, you can always put more on, but it's not so easy to take it off, especially if it's gypsum undercoat plaster and it's starting to go off. It's all practice and hands on..


Roughcaster.
 
Put the post up at work at lunchtime & just got chance to check tonight....

Thanks guys!
A very prompt & thorough response - and loads of useful info. :D

Think I must be improving - I was even understanding the terms etc this time. As I've struggled on some previous replies! ;)

Thanks again.
 

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