I have a customer asking me to install a unfinished solid oak board for them, it is also unfilled? I havent come across a unfilled board before as most of what Ive installed has been prefinished. Should it be filled with Lecol 7500 mixed with the saw dust? It is going to be oiled as a finish I would appreciate any advise
Where does the floor come from? Timber yard or wooden floor manufacturer? If from timber yard, absolutely check the moist content first before you agree to anything!
Apparently from a flooring manufacturer in the u.s. It has been kiln dried to a moisture content of 7%
7% is very low. Make sure it is left in the house at least 2 - 3 weeks before you start the works. Have you seen a board yet?
Sorry, its dried to 7% and then settles @ 10%. Its been in the house over 4 weeks now. I havent seen it but never seen unfilled wood full stop. I was a bit worried about it but it appears to be manufacturered by a company that does alot of this stuff? I will test it before I fit it anyway. Any ideas about the filling?
The main issue to look for is what the moister level was when it was milled! (tongue and groove etc added)
Can you still get problems if its acclimatised for 5 weeks and the area it is fitted in is a stable climate?
It only needs to be acclimatised for the period of time it takes to 'acclimatise'. Basically it may only need 1 day (it will always need longer than this! ) if the moister of the wood matches the moister levels of the room or if its miles away it may take longer than 5 weeks. The only way you will know this is by taking moister readings of the product, humidity and moister of the floor its being laid. For instance, lets say the floorboards in the house are reading 13% and your wood flooring is 8% then your product is not acclimatised to the subfloor you want to fit on. Or the product your fitting is showing low moister and the room humidity is high. The product needs longer to match its surroundings. This may take weeks hence its always adviced to leave in the area for a few weeks. I remember many years ago when i was fitting my first solid in a friends house, well actually it was a lad that used to work with me. The solid had been stored in a garage for a year. It was then left in the house for 2 months! Its moister content was still very high (i measured after it was installed and noticed gaps appearing) :? but in my wisdom we installed anyway! 6 months later and you could fit a coin in between each board. Moral of the story is to always test the moister of the wood! Dont presume because its been in the house for a few weeks its acclimatised. How do you know how the flooring was stored for the last year? As for the milling, if the product was milled when it was to dry or to wet the product wont fit together as it should or it may be warped etc after it is acclimatised. This is due to the product would of changed its shape/size from when it was milled to fit together. For example, the tongue could now be larger and the groove could now be smaller or vice versa. Or the wood has taken on its stable shape that was different from when it was milled. How many times have you been to a timber yard and picked up a piece of 3x2 timber that is shaped like a bomerrang or is twisted beyond use? The milling machine has not done that! It would of come out of the milling machine perfect and that has happened since due to moister differences etc.
I am a bit worried about where it comes from, like you say I dont know how its been stored. I have recently bought a testo 606 and the last four screeds I have put it on, including this one,have all read 10% so I guess if the wood is also 10% and the air humidity is ok it should be fine(I hope). I have always found with alot of solid boards the widths can be out by a good few mm. Is that down to milling at incorrect moisture levels?
if the boards are out from one end to the other as in size then it is down to milling normally. But to be honest im only giving you basic info here! If we went indepth we would end up with 5000 pages! Your meter, its not one i use but a screed moister reading is different to wood moister content. In the u.k we read in RH for testing concrete subfloors so basically british standards it should be below 75% RH (RH = Relative Humidity, maybe best known as that meter your grand parents had hanging on the wall trying to predict the weather, scale 0-100% and i guess always read around 60-70ish). However if installing wood flooring our BS is to high, it needs to be more like 65% and below. (do not confuse concrete moister v wood moister content, they are read a different scale) However we can use meters that use a different format. For instance a tramax i think uses a scale of 1-8% to read concrete. I think ( i need to check) but i think below 4% is dry and you need more like 2.5% to be safe? so if you meter uses this scale then your concrete subfloor sounds to wet, but like i say all these meters work on a different sacle. Hence teh british standard is below 75% and all meters that confirm to british standard use the same scale. Now the next issue is that the concerete subfloor CANT be drier than the humidity above it. So if the house humidity never drops below 70% then the concrete floor cant drop below 70% either. Its easy to drop the humidity in the house tho, this can be done by central heating. So over winter when the heating is on the humidity indoors will be lower but the concrete slab will normally be higher. Problem now is that the concrete slab is wetter than the air humidity above it. This is why you should install a surface DPM (epoxy etc) to control the subfloor moister. By doing this the woods moister is controlled by the humidity above it rather than the larger moister content below it that the wood will try and suck up like a spong. When the wood is allowed to take in the subfloor moister the flooring will cup or expand to much and blow off the floor. Anyway! Getting back to your meter. You need a wood species meter. I dont know of one meter on the market that you can test a peice of solid oak flooring and then test a pine floor and it automatically sorts out what the true reading is. Most good meters will give you a converstion chart to convert the two readings so you can end up with a true reading. Ideal you wan the subfloor (wood) to be the same as the product your fitting. You can have a 2% difference but thats the max. Now sometimes the subfloor (wooden) will read high. Some will try and acclimatise the product to it but the air humidity is to low to get the two floors acclimatised. When this happens its normally down to lack of airflow under the house. Air bricks are blocked, rubble under the floor or there is a moister bridge to the joists and the floorboards are sucking moister from the joists etc! In other words, before you fit a wooden floor you should understand what else can cause issues that can be easy to test for. Im getting Numb fingers now from writing this!
No, below 2% is dry (but one area in the whole area you're measuring, can have a reading of up to 2.5%). If the concrete is 4% then you can apply a liquid DPM, not if it is higher than 4%. Other point I just realised: the US floor specs are indeed dried lower than European standards, so the 7% dried sounds about right for this product.
Ok now im feeling a bit stupid, I have realised there are 6 settings on this meter, 2 for different types of wood, cement screed, concrete, anhydrite screed, bricks, mortar ect.. The cement screed reads from 0.5 - 2.5. Ive been using the same setting for both, I have only had this thing a few weeks. Even with the cement screed setting you couldnt use it alone as a moisture meter could you? I have always used a hygrometer, but I always put down a dpm if im sticking a wood floor. I will find out the rh of the sub floor soon. I never thought to test the air humidity I will do that when I go back I appreciate the information and advice
To start with, Karin (woodyoulike) can you send me some details of what meter you use and what scale it uses along with what is considered dry / wet etc. I would like to compare your standards to the BS standards and see what is the same. Be good to compare and finally come up with a converstion chart to use! Anyway..... Like i say, i dont know the meter your using and as 'wood you like' has corrected me on the scale it 'may' work on. To give you the best idea of what your meter works on i think you need to compare it to hygrometer readings. Im going to guess that if you get a reading of 2.5% then it is simular to 75% rh (woody i guess you will agree?) . I dont know to be honest as i have never used meters that are to BS ONLY and they read in RH only (0-100%). It is one thing that i want to start doing tests on at the new college to compare readings to educate myself. I guess that i shouldnt be doing this as it not BS but it would be nice to understand FULLY what other countries / foriegn colleagues use. Also dont forget that meters that "scan" the floor can not tell the difference between condinsation or read the trapped moister in the screed. They can only tell you what is present at the surface when your testing. Hence a hygrometer is left down for a couple of days and will give you a idea of how much moister is released from the screed. Not what is on the surface. The only meters that can do this is a hygrometer or a probe test that you drill the floor and insert a sleeve. You then test the moister in the sleeve after a few days. Both test are RH that is a range from 0-100%.
We (and most other Dutch, Belgium etc) floor fitters use this one: http://www.brookhuis.com/en/products/ha ... -meter.php The website has various PDF's (only some in English I'm afraid): http://www.brookhuis.com/en/downloads/h ... ontent.php you can request by email. Hope this helps?
I think we have one of them somewhere! But i ment what meter you use to measure the concrete moister not the wood. Cheers!
That's done with the same thing, you just change the pins and change the settings to measure concrete ;-)
Are you drilling holes and doing a gel bridge test or simular with it then or just scanning the surface, i.e pressing the pins against the surface?
Neither. You ram the pins into the concrete (see the metal bit? that's the "plunger" and forces the pins into the concrete, like a mallet?) and take an instant reading.
O.k, so how do you ram the pins into hard concrete, like power floated etc. How deep do you hammer the pins in?
