Remember, this is coming from a finish carpenter’s perspective and involvement with the build and thinks he has half a clue. So I am trying to include as many details as I can for those that might know some of it, but are not so sure about all of it.
Now you are almost ready to start putting in the floor system. This is where my buddy at the builder’s merchant comes in, I gave him a copy of the plans and he did the material take off for me, it saved me a lot of time not having to do it myself.
A Good Idea, while at the builder’s merchant or lumber yard, pick up a pressure treated stair stringer (just one) for the height of your new floor, you can use this as a pattern to make 1-2 or 3 sets steps to get up and down from the house, it just saves time on figuring one out.
This is also a good time to schedule your log home kit delivery and the crew to put it together. Let them know your starting the floor system and will be ready in a week or whatever you think it will take to be ready for them. Allow for inclement weather.
Also, if you plan on having some trusses made for the roof it would be a good idea to check in with them, these can be taken off the plans but if the final measurements don’t match the plans your trusses will not fit properly, my company chose to wait until the logs were up and then came out to the site and got an accurate measurement. I was concerned about the delivery time at this point, but they said they would put off other jobs and get mine made right away, and they did I had my trusses in a week.
First, I’m going to run through the checking for square rule and this doesn’t change. Please excuse my rough homemade sketches,
(left)The diamond shape, to adjust move the short corners out until both
diagonal measurements are equal.
(right) with 3 sides equal and one side being shorter or longer the same applies, move the sill plate in or out and check the 3-4-5 measurements and diagonals to get them where they need to be.
(below) is where you need to be, equal all round, level, plumb and straight. Should you come up with an out of square measurement bring it to the mason’s attention before the pots get filled, this will save a lot of problems, now he is aware of it and should offer you his solution to the problem, and let him show you his solution, if its not going to give you what you need he will have to fix it.
I could have made my mason fix it (one of the perks of being the owner builder) but it was easier and quicker for me to make the adjustments with the sill plate ( it wasn’t going to be seen or noticed anyway). Where you get the adjustment on this is the sill plate needs to be set back from the outside edge of the wall a half-inch to five eights for the plywood that attaches the floor (bands) perimeter to the sill itself, so don’t worry as long as you end up flush or just over the edge of the wall, the bottom siding logs (skirting) will cover it.
Where to place the lumber delivery for the floor. This is best located close to the side of the house facing in the same direction the joists will be laid out this just makes it easier to transfer them to the inside of the foundations without having to lift and turn each one, simply drag it over the wall to its final position, and with the sheeting for the floor try and get it close to the the corner you will be starting at.
Now that you have everything figured out you can set the sill plate, just remember when marking out where to drill your holes for the anchor bolts to allow for the back-set and any other adjustments you needed to make.
The next step is to start marking out the sill plate for the floor joists and the location of the walls that will be on top, I found it easier to first mark out where all the walls will be for the rooms above as these need to have double joists for support, do this on all the outer walls, do this in pencil to start with then once you are sure its where you want the joists to go then use a red or black marker to confirm the final position, now you can mark out all the joists.
A good idea, all the lines you are marking are for the center of the joist, if you make your mark 3/4″ to the left or right of the center line and put an X where the center is, this will tell you which side of the line to put the joist as you won’t see the centerline with the joist on top of it, and also make this mark on the outside face of the sill plate so that you can transfer it to the top of the band.
Start on one side and mark off every 16″ from one end to the other then go to the other side and do the same. Pointer, depending on the depth of your house, at some place or other the joists will overlap, which if you have two joists don’t forget to add the 1.5″ difference to allow for this and be sure that every 4 and 8ft on the joist layout is exact, this is where the seams on the 4X8 flooring will be.
Now we build the drop-down Girders that sit on the piers to support the joists, these will be three 2X10’s thick so it’s better to build them in place, as they get really heavy when you get to 30’or 40ft long. At this point, you can also check to see how level all the piers are this will determine how much you need to shim up the girders to get them level and take up any slack, it’s not rocket science there will be some shimming to do.
Lay these out flat on top of the piers, being sure that wherever there is a joint it will need to fall on top of a pier, once you have two layers in place nail them together then turn it over and lay the third layer on and nail these together, then just turn the whole thing upright (you may need two people for this part) and you should be good to go with the floor joists.Good Idea at this point is to get the outside bands nailed on, on the three sides leaving one side off where the joists were placed at delivery
I had to make four of these for my floor system, it should have only been three but somebody made a mistake on the (generic) plans and no one caught it, not even the Inspector. It wasn’t until I got two-thirds of the joists in place that it became apparent that the span for one section of the floor would not reach the girder, even if it had of reached it would have been more than the code allowed for the distance (check with your inspector).
So now I had to get my mason back to build the extra piers (it took 4 days to get him back because he was busy on another job) “and I had to build another girder”. This was another expense I could have done without.
All the joists are now in place and on the inside of the foundation walls where they need to be, now you can nail on the last band to the sill plate, transfer all your lines up to the top of the band and get all your joists nailed off.
Having all the floor joists all set and nailed off, you can now start the 4X8 sheeting. This is where your groundwork being right and whatever adjustments you had to make comes in. Your first sheet should fit right on there and be flush on the edges with the starting corner. Don’t forget the glue.
IF IT ISNT RIGHT you can do this, check the 3-4-5 rule again, if it’s still off, do this,(2x10s will sometimes bow when drying out, even if nailed down at the bottom) pull two string lines along from the starting corner to the ends of the walls your starting at and follow the line, if the joist end wall is straight and its the band on the adjacent wall that’s bowed nail the straight edge off and pull or push the adjacent band in or out to the string line, if its within a 1/8″ and the 3-4-5 is good just follow the string line, and as you continue nailing the first sheet down, make sure the 16″ o/c is where it should be, as this will affect the seam lines and check every sheet as you go. If you get this part right you should not have any more problems (unless the log crew messes up). FYI, you will need at least a case or more of flooring liquid nails to glue the sheets down as well as nailing them.
If you worked all the timing right your log crew will be there in a day or two, this now gives you time to mark out where the doors and windows will be and to mark out where you need all the electrical outlets and light switches on the exterior walls. I did not have this time as I was already four days behind, and they were a day early and the floor wasn’t finished, needless to say, they didn’t seem mind too much and jumped right in and helped me get it finished and worked with me on marking out everything that needed to go into the walls. For a small fee, of course. (this is part of the unforeseen miscellaneous money that you set aside at the start of the build). Now that the floor is finished its time to mark out where all the doors, windows, electrical outlets, and light switches will be, as these all need to be put in as the logs go up.
Hi there Dell.
You've put together a very informative article, so great work!
I love how you approached the Mason directly, based on seeing his current project. I think that more people should directly approach tradesman if they admire their work (it can't hurt can it).
This makes me want to start a building project in my spare time.
Take care mate,
Thanks for the pointers. My husband and I are currently designing our off-grid cabin and I think we've already changed it at least 3 times. You've given me a lot more to think about, we will be building it on property that we already own so that takes one headache away. I'm going to keep reading to see what else I haven't thought of.