inverted peak in ceiling plasterboard

[tiffy]

Hi,

Just bought a house and I am renovating, I have a problem with the ceiling, I have googled many combinations, but have come up with nothing, I have lines accross the whole of the ceilings in the large rooms of the house, I think but I am not sure that they are due to inverted peaking only because I saw it on another site, I have put a broom handle and applied pressure and there would only be a centimetre give, so I don't think it has sagged but hey I don't know too much about this! I would like to fix this or get a proffessional but until I know what it is I am a little stuck, I am sure I am not the only one with this problem I just don't know what it is called any help would really be appreciated.

[Barry_White]

Tiffy

Welcome to the forum. If you could post a picture it would help to let us know what you are talking about. The only thing that I could think that it could be is that the joins in the plaster have not been finished properly.

[tiffy]

thankyou will do that on Monday afternoon when I go back, a friend did look at it and said it was a real cr-ppy job, its nice that you took the time to answer thankyou.

[rod@plasterbrok]

Here is a good link regarding peaked joins.

http://www.fwcianz.com/cgi-bin/page.cgi?id=160

They are easily repaired by a competent plasterer.

Contrary to the advice in this link I would not normally try to sand out or scrape back the peak, I re trowell the joins with top coat. Maybe 2 coats if required and never see them again.

Sanding back through a painted surface is not that easy.

Cheers Rod

[tiffy]

Yes this is where I got my original info from, and going by the diagram I gathered I had an inverted or "dip" in the ceiling where the boards meet, I am a little worried about the cost though as the tradies around my area are flat out on a new housing estate and may charge me like a wounded bull, could I do it myself?

[rod@plasterbrok]

Anyone could do it i guess, if they went about it the right way. Use an all purpose compound that with at least 2 coats. Dont try to apply it too thick. If you use a 12" joint knife and just start with a thin coat you will easily see where fill is required for the next coat. All purpose compound is easily sanded, therefore when you sand back be carefull that you don't over sand the joint.

The high spots that are painted will be hard and if you sand too much you will end up sanding away the top coat and leaving the peak again. I sand back just enough to barely expose the high spots through the top coat. If you need to sand more to get rid of trowell marks etc. then stop sanding and fill over it again rather than sanding too much.

Try a couple of joins and see how you go you have nothing to loose.

Cheers

Rod

[tiffy]

It really does show what good spirit some people have, that they use some of their time to help others for no personal gain, and you must be one of these people.

I will give it a try BUT after reading the sanding bit I may try again to get a tradie to give me a quote, although Perth is a little busy at the moment and everyone will tell you a good plasterer is like hens teeth

Thank you for your time

[pawnhead]

I find it handy to use a straight edge against the surface to find exactly what needs filling, after you've sanded/scraped back the higher points. A wide, straight broadknife might be good enough. Use a pencil to mark the outlines of the depressions, then you can see exactly where you need to fill to. Don't use a biro or it will keep bleeding through the paint. After a light sand, and a re-check, you may have to re mark and fill again.
If there's a high ridge that's hard to sand or scrape, then fill a bit each side of it and try to make a mound with a smooth transition instead of a sharp peak. Sand back just enough to barely expose the high spots as suggested by Rod, then check with a straight edge each side of the mound.

It's difficult to tell if everything is OK without using a straight edge, but it becomes more obvious when the paint goes on.

You can also run your hand back and forth over a joint, and if it's uneven you can feel undulations that are hard to see.

[tiffy]

Well I gave it a try, and it took a bit to fill in the dip I can tell you! Then sanded it, thank god it was only the laundry, it was a hard job I can tell you, not something I would do for a job, (sorry rob). So I spent the day on the phone, and found someone who came around that day, and when he said he was going to show up! He has worked on a friends house and said my ceiling job was never finished off, has not been glued, and has sagged slightly so he is going to re nail it, filled it and sand it, said it would take 2-4 days and charge me $100 bucks a day plus materials, so all I can do is hope it works out! Thanks I will let you know this site is so helpful spent the day researching on the site, i am about to embark on flat pac kitchen from bunnings but thats another thread!