Domestic tradesmen - flooring advice required please

[Atik]

As you may know, we have recently bought a house and currently nearing the end of the major works required (part electrical rewire as the house was equipped with one single socket in each room! plus a full gas central heating install). Anyway, as some of the floorboards havent been touched since being fitted in the 1930s, when prising them up, a few of them splitered to destruction meaning some new 20.5mm floorboards were required.

Also, I have found evidence of woodworm... to the point where some seemingly fine boards were like powder on the underside! Now, I know its treatable and already have the Cuprinol stuff ready for tonight. I wont be taking chances with the flooring and will be ripping up every single board over the next week.

My question now is, when I'm putting the new boards down, can I fit them at an angle to the joists? Is there any building legislation preventing me doing this? I know that I'll use more boards as there will be more waste due to the angled cuts at the walls, but if I'm doing this, I might as well do it the way I'd like to the first time!
flooring.JPG
If I can put them diagonally, which way of fitting would be best? Cutting the boards at an angle or straight (see pic)? I suspect going at an angle will mean that any screws going in at the end of the boards may cause the board to split? It would be tongue and groove boards going on by the way, directly onto the joists.

[miller]

Option 2 would be best if fitting diagonally.

If the joists are standard 38mm thick It doesnt leave a great amount of fixing coverage on a board joint. How big are the rooms that warrant an actual cut in the board length? Can it be done in a single length?

I would also plan all joints away from areas of high traffic, less chance of stressing the joints?


Whats the maximum length in the floor board you can get? How big are the rooms?

[Atik]

Standard joists fitted throughout I think. See pic. The lines on the page are the direction of the joists.

flooring2.jpg

I can get hold of the following (in preference order)
option a ) 2m long sanded and finished boards as I can collect them myself
option b ) 3m long sanded and finished boards at additional cost of delivery
option c ) 4m long reclaimed boards but these wont be sanded or finished so I'll need to factor that into the final cost. With the additional cost of hiring a sander and delivery times and cost, it works out about the same as me just buying boards from Wickes!

I would no doubt be planning on placing joins away from traffic areas and near potential access areas (near rad pipes, electrical connections etc).

I reckon I may end up going for the angled cuts and drilling pilot holes in the board for all the screws going into the ends.

[TAR]

My question would be why?

is there a reason why you want the boards at that angle?

[aboo]

I would go with option 2 as well if that's the way you want to fit them. To top them splitting when screwing them down your best to bore the hole hole first.

[Atik]

Tim, its purely for an aesthetics thing. I like the look of angled boards. In fact we are fitting angled flooring downstairs, so we wanted to carry the theme upstairs.

Downstairs is a concrete floor so no joists to stick to, just put down the underlay and the flooring.

[Nick Mann]

By putting them on the p!ss you would be increasing the span of the board, effectively increasing the gap between the joists. I'd imagine that would give more flex to the boards. I have no idea at what point it contravenes building regs though.

[exevoowner]

Isn't it something to to with strength with the boards at 90 degrees to the joists in affect making them none movable were as if you fit them as you want then you'd weaken the construction but there is a way around it double board with the top in the direction you want

[Atik]

Double board is effectively twice the cost! But I see your point. It was a consideration, but I think one set of boards at 20.5mm thick is sufficient enough.

The difference between boards fitted at 90 degrees and 45 degrees, provided both are screwed down to the joists and are tongue and groove 'locked' into place would be absolutely minimal on the joists. I don't see that a 'locked' square (between the boards and joists) is any weaker than a 'locked' parallelogram, and anyway, the joists are designed to not have any movement as they are blocked into the brickwork. I know that over time joists can sag and warp but I don't have any of those issues.

I know I'd be increasing the span of the boards, and that's what I was looking to find out, if there was any regs I'd fall foul of. IIRC standard joists are 18" apart? I figure I'd be making the span run about 22-24", and on 20.5mm boards, that should be plenty strong enough.

I'll keep Googling and maybe have a chat with the local building regs offices during the week.

Exciting times!

[Nick Mann]

If cost is a consideration then go for chipboard sheet flooring and then put a thinner real wood over the top? You could glue it then too, removing the screw heads from the equation. It would also have more strength.

[Davezj]

are the boards upstairs or downstairs?

as the floors are old do they have noggins inbetween the joist. if not it would be very beneficial to fit them as this will greatly stregthen the floor and illiminate any bounce.
this is something i wish the previous owner of my house had done. i don't have noggins downstairs and the floor bounce badly as every joist is directly taking all the weight that is ontop of that particulr joist rather than spreading it accross the entire floor.

is the current reg for new build and replacement floor 400mm (16") on centers for floor joist now? (plus niggins fitted)

[Atik]

Downstairs is all concrete so no problems.

Upstairs is where I have the problem. There are small diagonal noggins between the joists which is good. The plumber found this out as he was trying to thread his pipework and kept hitting the 'crosses' inbetween the joists. Im happy with the joists that are in place. Even where the joists overlap at the middle of the house (on a brick wall) they are secured to each other. Its just simply the boards need to go due to the woodworm.

I think we will be going for the reclaimed floorboards throughout now. I'll be drilling pilot holes for all screws at the end of each board and maybe even adding a few spots of wood glue at the board ends. Spax flooring screws throughout to give the floor a proper perfect finish.

[miller]

Like Nick mentioned it may well be worth the intial investment of a thin chipboard layer, on this you could add a thin layer of 'fuzzy' insulation then your wood boards which will beef up your heat retention PLUS thin down noise transfer above and below which can be crazy with wood floors.....

Wood floor noise from above would drive me stir crazy so at this stage I would be doing all I can to dampen it down!

I know I worked on design of a set of apartments in Newark in an old pump house....wood floors throughout, noise was a major issue. We had to add layers to floor and ceiling to try and keep noise transfer down.

You will pat yourself on the back in the future, trust me!

[Atik]

Cheers Mike.

I already had plans to add 'loft insulation' before the new boards go down. Do you think that will be enough? I may be tempted to go for two layers of it if that would be better for heat retention and sound deadening. IIRC I saw some stuff that offered around 20dB sound reduction, so doubling up would be pretty good I reckon?

[TAR]

Atik, beware of using loft insulation around electric cables as it can dramatically increase the heat they generate.

[exevoowner]

if it woz my place then i would first off think of every option for each room and future proof it like tv point ,phone point and a like then use chipboard as a sub floor then floor boards on top

[Atik]

Cheers Tim, I'll bear that in mind. The electrics run along a single set of notches in the joists so it would be easy to to avoid them.

Nige, I have already run my satellite and broadband points through the house to the back room. In fact it was the first thing I did!
I'm still umming and ahhing over adding chipboard first. That would take the flooring to near 40mm from the joists. Further meaning I'd need to chop doors down a fair bit. That then also means the skirting boards wont sit over the boards, and I'll need to add corner beading to make it sit right

Argh!

[exevoowner]

adjust the thickness to suit what you need it to be not the other way round 10mm board then 10.5mm floor board