A variation on the floor glue/screw conundrum.

[epsilonGreedy]

51 sheets of Eggar Protect (60 day exposure) arrived today and my first floor posi joists are due on Wednesday.

 

I have a pro carpenter lined up for Thursday/Friday and he reckons the two of us will have the 60m2 job done by EOD friday.

 

The pro carpenter says glue + plus a few nails per sheets from his nail gun + 400mm centers + 22mm board + my overspecced joist chord dimensions will equate to a rock solid floor. He says fixing the boards with screws is an unnecessary complication.

 

I am inclined to agree with his plan because I will likely use up the full 60 day exposure limit before the roof is felted and the worst of the weather is kept off the first floor. My concern is that additional screw holes will create water ingress points.

 

The Question

If I fit the floor with glue + nails would it create problems if I then later doubled up the nails with additional screws once the roof is on?

[jack]

What does Eggar say?

 

I seem to recall that for at least one flooring system, the preferred approach for minimal noise was nails (or was it screws?) at one end, and glue-only on the remaining edges. 

[epsilonGreedy]

3 minutes ago, jack said:

What does Eggar say?

 

I seem to recall that for at least one flooring system, the preferred approach for minimal noise was nails (or was it screws?) at one end, and glue-only on the remaining edges. 

 

 

Good point, I will give Eggar a call tomorrow. In my experience of phoning large organizations is working pretty well in the middle of Covid epidemic because staff are no longer distracted by meetings, appraisals and all the other distractions of office life.

 

The minimal nail approach you describe sounds like my carpener's plan. I wonder if that low-noise plan works best with a glue that does not set as hard as the foaming D4 stuff. One concern I have about retro fitting extra screws months after the floor is down is the possibility that the clamping actions of the additional screws might crack the glue bond.

[Mr Punter]

My favourite would be D4 glue on joists and all board edges and a few Paslode nails to hold the boards in place.  Leave a perimeter expansion gap.  Fit screws after you are watertight.

[ToughButterCup]

I went for screws and D4. Didn't take long once I got an efficient work flow.

(146 m sq)

[Oz07]

Just nail the first row to keep it straight. Honestly that glue goes off so quick. If you get any troublesome bits over hangers that aren't sitting flat perhaps screw these while the glues goes off then remove screws later if you wanted

[Oz07]

Also depending how complex the layout 2 days is plenty. I can do a pair of semi's in a day with a good labourer

[epsilonGreedy]

1 hour ago, Oz07 said:

Also depending how complex the layout 2 days is plenty. I can do a pair of semi's in a day with a good labourer

 

 

Interesting. We have two chimney breasts, one stairwell and it is an L-shape floor plan. Two days includes lifting the metal web joists into place and fitting the floor sheets down.

 

The pro carpenter probably adjusted the estimate for the poor fussy labourer i.e. me.

 

He has also quoted two days to get the roof trusses fitted and that is for 1 valley, 3 chimneys and 5 hips. However he reckons we will need an extra body to help hoik the trusses up manually.

[PeterW]

Are the brickies staying on site to block in the ends as you do the joists or going back after..?

 

Don't forget the Tony Tray...

[Oz07]

2 days is fine you're not going to do it in one if complex and nobodies going to kill themselves to earn half a day the next day. 

I would guess his truss estimate is miles out. Something like that take a Joey and me a week with all the bits and pieces, valley boards fascia soffit etc

[epsilonGreedy]

3 minutes ago, Oz07 said:

I would guess his truss estimate is miles out. Something like that take a Joey and me a week with all the bits and pieces, valley boards fascia soffit etc

 

 

He gave me the roof quote when he was idle at home, this week he was back on site as things opened up here. My favourite BM started site deliveries today.

 

The roof quote excluded fascias/soffits.

[nod]

4 hours ago, epsilonGreedy said:

51 sheets of Eggar Protect (60 day exposure) arrived today and my first floor posi joists are due on Wednesday.

 

I have a pro carpenter lined up for Thursday/Friday and he reckons the two of us will have the 60m2 job done by EOD friday.

 

The pro carpenter says glue + plus a few nails per sheets from his nail gun + 400mm centers + 22mm board + my overspecced joist chord dimensions will equate to a rock solid floor. He says fixing the boards with screws is an unnecessary complication.

 

I am inclined to agree with his plan because I will likely use up the full 60 day exposure limit before the roof is felted and the worst of the weather is kept off the first floor. My concern is that additional screw holes will create water ingress points.

 

The Question

If I fit the floor with glue + nails would it create problems if I then later doubled up the nails with additional screws once the roof is on?

Once they are glued and nailed 

no need for anything 

 

it won’t take you long to put 60 m2 down 

 

I had a 130m2 and covered them with visqueen and battened it down 

It was exposed Jan and Feb 

Wen up each day and brushed the water dow where the stairs where going 

Looked like new when I removed the plastic 

[epsilonGreedy]

1 hour ago, PeterW said:

Are the brickies staying on site to block in the ends as you do the joists or going back after..?

 

 

Coming back after. My main brickie lives in the village but we have not discussed the finer points of masonry around the joist ends, have I overlooked something?

 

1 hour ago, PeterW said:

Don't forget the Tony Tray...

 

 

I read that blog while buying my plot and much of it went over my head at the time. I recall your response to my question over a year ago about how air permeable is a masonry block and you suggested observing how quickly water can wriggle through a block. My plan for making the inner block wall airtight was to brush a runny cement/sand screed over the inner face of block wall once at wall plate height.

 

We will probably move into the part complete house before much of the ceiling is up hence I was hoping the heating will expose any joist wood shrinkage before I run some flexible foam sealant at the joist ends prior to closing up the ceiling. This is just my idea and not the result of any research.

[nod]

3 minutes ago, epsilonGreedy said:

 

Coming back after. My main brickie lives in the village but we have not discussed the finer points of masonry around the joist ends, have I overlooked something?

 

 

I read that blog while buying my plot and much of it went over my head at the time. I recall your response to my question over a year ago about how air permeable is a masonry block and you suggested observing how quickly water can wriggle through a block. My plan for making the inner block wall airtight was to brush a runny cement/sand screed over the inner face of block wall once at wall plate height.

 

We will probably move into the part complete house before much of the ceiling is up hence I was hoping the heating will expose any joist wood shrinkage before I run some flexible foam sealant at the joist ends prior to closing up the ceiling. This is just my idea and not the result of any research.

I wouldn’t worry about water ingress on the inner leaf of blocks

Once the roof goes on they will go and stay bone dry 

[epsilonGreedy]

14 minutes ago, nod said:

 

I had a 130m2 and covered them with visqueen and battened it down 

It was exposed Jan and Feb 

Wen up each day and brushed the water dow where the stairs where going 

 

 

Just been to the visqueen site after reading your message, would I be correct in thinking this is recommended over some ordinary DPM block sheeting because it lets some water vapor escape and so reduces condensation?

 

18 minutes ago, nod said:

Looked like new when I removed the plastic

 

 

Having spent two weekend laying on the ground cleaning up 3 courses of engineering blue bricks below DPC I am now all in favour of keeping things clean. Does the visqueen create a slip hazard when the brickies are bringing up the inner brick wall to wall plate height?

  

[PeterW]

11 minutes ago, epsilonGreedy said:

Coming back after. My main brickie lives in the village but we have not discussed the finer points of masonry around the joist ends, have I overlooked something?

 

 

 

Use a bit of 3x2 sprag nailed to the ends of the joists to keep them square and straight as they will move when you are boarding otherwise. With only a 100mm bearing end you can soon knock them out of line and a fall becomes very easy. They will also move when you drag boards over them.

[epsilonGreedy]

9 minutes ago, nod said:

I wouldn’t worry about water ingress on the inner leaf of blocks

Once the roof goes on they will go and stay bone dry

 

 

Sure, the water permeation experiment was just to illustrate how air permeable a block wall is. The only inner wall I am trying to keep dry the one done in facing brick because when the mortar gets wet it changes colour once dried out. Seems to be a hazard relating to the white cement.

 

@prodave's multiple posts on the fallacy of the airtight plasterboard tent have lodged in my head so I intend to put some effort into creating a half decent air tight inner wall shell. 

[joe90]

My Egger board floor was laid  by my builder (cus I was ill!) and he used a few nails in the first boards to stop them moving, then only glued all the rest with d4 and it’s solid as a rock. Out in a very wet winter fir months (I was worried about damp in them) but once the roof was on and dried up the floor was fine .

[epsilonGreedy]

10 minutes ago, PeterW said:

 

Use a bit of 3x2 sprag nailed to the ends of the joists to keep them square and straight as they will move when you are boarding otherwise. With only a 100mm bearing end you can soon knock them out of line and a fall becomes very easy. They will also move when you drag boards over them.

 

 

Would you believe it, since your first post my carpenter sent a txt asking if I have any "roof lathing". He must be thinking along the same lines as you.

 

Now where to source that in a hurry in a country in lock down!

 

Though hang on, the joist manufacturer is supplying a load of wood for the perimeter noggins, would that not provide mid job joist stability?

[PeterW]

Perimeter noggins and Z Clips..?

 

They will still twist and move - only 2 nails in a Z Clip and you're not going to nog all the bottom chords as you fit them though.

 

 

[nod]

9 hours ago, epsilonGreedy said:

 

Sure, the water permeation experiment was just to illustrate how air permeable a block wall is. The only inner wall I am trying to keep dry the one done in facing brick because when the mortar gets wet it changes colour once dried out. Seems to be a hazard relating to the white cement.

 

@prodave's multiple posts on the fallacy of the airtight plasterboard tent have lodged in my head so I intend to put some effort into creating a half decent air tight inner wall shell. 

If you are worried about airtightness You can use a gypsum parge coat 

Creating an airtight envelope plays a large part of my business and can easily be achieved regardless of block or brick type 

Some have there theory’s but I’m at the practical end everyday 

While most on here are looking the create airtightness for heat loss

In my business largely commercial 

The reason for achieving airtightness is fire protection 

No grey areas here A plasterboard airtight envelope IS achieved 

and checked and re Checked

The same principle can be applied to your homes 

While I’ve good general building knowledge 

Ive Forty years experience doing this commercial 

Designing and implementing large commercial contracts 

Your house is very easy to make airtight 

With just a little care 

 

[Russell griffiths]

@epsilonGreedy have you looked at the blower proof liquid, I have a tub and I looks like good gear, you can get a sprayable version that you can blow into all the nooks and crannies. 

[epsilonGreedy]

5 hours ago, nod said:

If you are worried about airtightness You can use a gypsum parge coat 

Creating an airtight envelope plays a large part of my business and can easily be achieved regardless of block or brick type 

Some have there theory’s but I’m at the practical end everyday 

 

 

You mentioned the gypsum parge solution to air tightness last year and at the time I ignored this because I am unfamiliar with the material. Would I be correct in thinking such a parge coat that will be hidden behind plasterboard, does not require great skill to apply?

 

By contrast sand/cement slurry applied with a broom does seem more diy friendly.

[epsilonGreedy]

4 hours ago, Russell griffiths said:

@epsilonGreedy have you looked at the blower proof liquid, I have a tub and I looks like good gear, you can get a sprayable version that you can blow into all the nooks and crannies. 

 

 

No not heard of that before, I will look at the video later. With a big tub priced around £100 I think the sealant would be best used for treatment of specific areas such as service penetrations or joist ends. I think I have 200 m2 of internal block wall.

[epsilonGreedy]

15 hours ago, joe90 said:

My Egger board floor was laid  by my builder (cus I was ill!) and he used a few nails in the first boards to stop them moving, then only glued all the rest with d4 and it’s solid as a rock. Out in a very wet winter fir months (I was worried about damp in them) but once the roof was on and dried up the floor was fine .

 

 

This is reassuring to read, reckon I am looking at 2 to 3 months of summer weather exposure. As it happens I ordered Norboard Caberdeck+  which has a harder light grey plastic laminate finish with an anti slip pattern embossed. The other stuff I have seen (probably Eggar) has a matt grey finish in what looks like a viscous paint.