Warped new wooden worktop, why?

[bretthalliday]

I have installed a solid wood worktop from IKEA. IKEA say that it has been pre-oiled and all you have to do is oil it 5 times a year. I fixed it just with two screws at the front, the worktop bridges over one kitchen unit (which contains a built in dishwasher). Because the dishwasher is plumbed in, I cannot remove the dishwasher to let me fix the worktop at the back. Once installed I oiled the top surface 3 times with IKEA oil (a mix of linseed oil and water). Within 6 weeks the worktop had warped dreadfully (being about half an inch depressed in the middle compared to the front and back edges. The kitchen has not yet been used, so the warping is not the result of the worktop getting wet. I am going to buy more wood from IKEA, will that warp as well? This time I planned to oil both top and bottom prior to fixing.

One end of the worktop overhangs by about 20 cm, so I suppose I could fix a metal angle bracket along the depth there. Would that stop it warping? The funny thing is that when you go to IKEA restaurant, they have these wooden tops on the tables and they don’t seem to be supported at the edges and yet they are as flat as flat. I am sure they get lots of drink spills on them and still they look OK!

Untitled

• bretthalliday
• 7 Feb 2009
• 1

 

[big-all]

heeelllooo and welcome bretthalliday

is the worktop fully supported along the length under the edge the ruler is on !!!
you only have around 30% strength accross the grain so it will readily sag especialy if steamed

i believe you should also apply a foil type protection above dish washers!!!

have a look at the edges on the ikea tables and you will have an incert or a mitred edge to give support to the edge or they may even be chipboard with wood effect formica or simmilar

 

[bretthalliday]

No the edge is not fixed at all, about 20 cm overhangs at the end. I guess with my next attempt I will oil all sides of the wood first, and then try and fix as many edges as possible, but this will not be easy with the dishwasher in the way. I really can’t move the dishwasher away because it has very frail legs and will not slide in to place. I need to almost lift the dishwasher into place without the worktop in the way.

Thanks for the tip about the foil protection, a strip of metallic looking stuff did come with the dishwasher, now I know why!

But what surprises me is that the wood warped even though the kitchen has not yet been used. There has been no heating in the building, could the extreme cold have made the wood warp?

Do you fix screws tight, or a bit loose to allow for wood movement? I read somewhere that the holes you drill in the base units should be big, and then use a washer to fix the screw from underneath, through the over large hole and then into the worktop to allow movement.

 

[big-all]

if your short off space underneath at the end you can use a length of angle iron [assuming its not oak] affixed to the wall where the end should be an inch short you can then rebate behind the front edge on the end and underneath for the bracket to sit in without showing in normal use as its screwed into the wall in the area covered by the the worktop end

or use some normal worktop slotted brackets to give support every 150mm across the end grain

and yes you have an extended slot where the head is
the wood will only expand accross the grain [back to front]

 

[bretthalliday]

Thanks for that, I'll give it a try!