Any builders? How long does it take for mortar to go hard?
Discussion
I laid my first row of concrete blocks on Sunday morning, on the double garage project, but this morning the mortar is still crumbly, almost like it has no cement powder in! It looks and feels like hard brown sand, and can be crumbled to nothing if you break a chunk off and squash it between your fingers. I mixed in about 5:1 sand to cement. It's been there almost 48 hours now, so something good should have happened, surely?
It has been kept covered in polythene sheeting, there's been no frost either. I want to get on with it while the sun is out but I'm loath to lay more blocks then find it all falls down.
I had a day off yesterday as my back ached so much after loading all them 140mm blocks into the footings.
It has been kept covered in polythene sheeting, there's been no frost either. I want to get on with it while the sun is out but I'm loath to lay more blocks then find it all falls down.
I had a day off yesterday as my back ached so much after loading all them 140mm blocks into the footings.
Should have gone off enough to be "hard" in 48hrs though no matter how damp it is. It's a chemical reaction afterall, the environment only matters if it's really high humidity + direct rain or really low humidity + direct sunlight...
Would it really get properly hard over the next 30 days if it's crumbling to the touch after 48hrs? Sounds rogered to me!?!?!?
Do all my pointing at 4:1 and it's hard as nails even in this kind of weather
Your bag of loddy gone off a bit already in the bag with the damp?
Dave
edit: sorry 3:1, 4 parts overall... this is why the ridge tile pointing goes slightly orangey towards one end where I did a 4:1 batch
Would it really get properly hard over the next 30 days if it's crumbling to the touch after 48hrs? Sounds rogered to me!?!?!?
Do all my pointing at 4:1 and it's hard as nails even in this kind of weather
Your bag of loddy gone off a bit already in the bag with the damp?
Dave
edit: sorry 3:1, 4 parts overall... this is why the ridge tile pointing goes slightly orangey towards one end where I did a 4:1 batch
Edited by Mr Whippy on Tuesday 28th November 11:37
ZR1cliff said:
If its below ground level i mix 3:1 and above ground 6:1,its been very damp lately and will take a time to go 'OFF' so dont worry too much.
DONT put washing up liquid in the mix.
DONT put washing up liquid in the mix.
It's basically below ground. I did add a bit of plasticiser to it
Not the end of the world is it? I reckon I'll backfill the first row with more concrete, rather than take a chance, I have a mixer and loads of mixings to use up. It'll all be out of sight at the end. Mr Whippy said:
Should have gone off enough to be "hard" in 48hrs though no matter how damp it is. It's a chemical reaction afterall, the environment only matters if it's really high humidity + direct rain or really low humidity + direct sunlight...
Would it really get properly hard over the next 30 days if it's crumbling to the touch after 48hrs? Sounds rogered to me!?!?!?
Do all my pointing at 4:1 and it's hard as nails even in this kind of weather
Your bag of loddy gone off a bit already in the bag with the damp?
Dave
edit: sorry 3:1, 4 parts overall... this is why the ridge tile pointing goes slightly orangey towards one end where I did a 4:1 batch
Would it really get properly hard over the next 30 days if it's crumbling to the touch after 48hrs? Sounds rogered to me!?!?!?
Do all my pointing at 4:1 and it's hard as nails even in this kind of weather
Your bag of loddy gone off a bit already in the bag with the damp?
Dave
edit: sorry 3:1, 4 parts overall... this is why the ridge tile pointing goes slightly orangey towards one end where I did a 4:1 batch
It is hard, you can't poke your finger into it as such, but it will crumble if you squash a chunk between your fingers. It is very wet/damp down there, but not underwater as such, and it has rained almost continually for the last day or so.
The cement is brand new, in sealed bags, bought a week ago.
I've just put the second row of blocks on and tomorrow I'll go point them up a bit and pour some concrete around the bottom and start filling the middle ready for 'the big pour' next week, assuming the lot don't fall over at the first storm to hit us....
cardigankid said:
That really doesn't sound right - don't build any more till this is sorted out. Was it lying out in the rain as it was being built? How quickly did you cover it up? You are sure there has been no overnight frost?
No rain while I was laying the blocks, no frost overnight. Too late about not building any more though, as I just put the second layer on
It could mean a lot of chipping and hammering to get the collapsed mess out of my garden in the next few months.
King Herald said:
cardigankid said:
That really doesn't sound right - don't build any more till this is sorted out. Was it lying out in the rain as it was being built? How quickly did you cover it up? You are sure there has been no overnight frost?
No rain while I was laying the blocks, no frost overnight. Too late about not building any more though, as I just put the second layer on
It could mean a lot of chipping and hammering to get the collapsed mess out of my garden in the next few months.
I know what you are going through, I built a large stone double garage myself three years ago, digging the foundations, roofing and tiling it, everything in fact.......never again...
... It will all be worth it in the end, although personally I would have waited till summer when it's light till 10pm....
willmcc said:
ZR1cliff said:
DONT put washing up liquid in the mix.
Long time ago now but I built a huge shed (steel frame but all breeze block walls) religiously adding a little washing up liquid to every mix, what did I do wrong?
Not to sure but when i was on site they banned the use of it saying it made the mix go all powdery,Febmix is the best additive for bricklaying muck/mortar.
Edited by ZR1cliff on Tuesday 28th November 18:37
Wacky Racer said:
I know what you are going through, I built a large stone double garage myself three years ago, digging the foundations, roofing and tiling it, everything in fact.......never again...
... It will all be worth it in the end, although personally I would have waited till summer when it's light till 10pm....
I tried mixing concrete tonight, by the light of the silvery moon, and a bloody great spotlight, but it was no fun: blinded looking in one direction, total pitch black looking in the other, so I gave up before I lost a limb in the concrete mixer.
The garden currently looks like a scene from the Battle of the Somme, ankle deep in mud, wish I'd waited until summer.
King Herald said:
ZR1cliff said:
If its below ground level i mix 3:1 and above ground 6:1,its been very damp lately and will take a time to go 'OFF' so dont worry too much.
DONT put washing up liquid in the mix.
DONT put washing up liquid in the mix.
It's basically below ground. I did add a bit of plasticiser to it
Not the end of the world is it? I reckon I'll backfill the first row with more concrete, rather than take a chance, I have a mixer and loads of mixings to use up. It'll all be out of sight at the end. [quote=Mr Whippy]Should have gone off enough to be "hard" in 48hrs though no matter how damp it is. It's a chemical reaction afterall, the environment only matters if it's really high humidity + direct rain or really low humidity + direct sunlight... Would it really get properly hard over the next 30 days if it's crumbling to the touch after 48hrs? Sounds rogered to me!?!?!?
Mate your just being over cautious,a bit like when i rebuilt my 4 cam motor for the first time,i was for ever wondering if i did it up right because i wasnt familiar. lol
Just to let you know as your probably wondering what a cabby knows about building,my trade is a bricklayer and i still do some during the day having in my time worked on sites and for myself during the last 30 years ,indeed i started laying bricks at the age of 12 in a childrens home so you see ime well prepped.
Mortars can dry in all sorts of times depending on the cement,weather and uses,they even pregnate premixed site mortars for times like 72 hours.
Your Garage,,,,,the damp course(DPC) should be atleast 2 courses of brickwork (6 inches or 150m) above ground level...up to damp course(DPC) do 3:1 cement mix,,,a febmix plasticiser is good to use as it makes the cement/mortar/muck more pliable.
Above DPC level you can use a 6:1 mix and add Febmix if you wish.
A little tip ,,if you work hard at getting up to DPC level and square you can then use 4x2 timbers as a profile ,setting one up at each corner making sure they are plumb then run string/nylon lines between each profile to run in the blockwork/brickwork.
But before...make sure that you set up the Garage door frame using two or more scaffold boards to steady the frame while you plumb(vertical) and make sure top of frame is level......then you can measure down from the top of the frame courses,in your case blockwork allowing 10mil for each joint..once youve marked this down the garage door frame you can then level transfer the marks to the 4x2 profiles this will help you in setting out for lintels above the garge door frame.
ZR1cliff said:
Loads of useful stuff
Thanks for the info. I'm doing the whole thing from concrete blocks, and the ones below the floor are 140mm, the rest 100mm. It is basically a 16' x 20' rectangle of two rows of blocks, which will be filled with rubble then concrete, with a membrane under the concrete. The DPC will then lay around the edge and the walls built on that. Total isolationg from the damp earth below.
I'm learning as I go here, so any help or advice is always welcome.
Sounds good ,before you lay the damp proof membrane(DPM) down make sure to blind over with sand so any jagged edges of rubble dont punture the membrane.
Do you have any other frames in the structure if so try to have "head of frame" all on the same level/course if possible it gives a cleaner look.
Are you plastering/coating the garage or is it face block work.
Do you have any pics or plans to show on here.
Do you have any other frames in the structure if so try to have "head of frame" all on the same level/course if possible it gives a cleaner look.
Are you plastering/coating the garage or is it face block work.
Do you have any pics or plans to show on here.
Hi If you are not a pro at mixing morter then measure the sand and cement in a bucket or similar. It is so easy to put large shovels of sand and not cement. so if you are not batch mixing try it and see if the morter looks stronger, 5-1 is a good above ground mix. It so simple but have seen results of poor mixing even on site
You can always crush concrete if you are determined, but mortar shouldnt easily crumble between your fingers. If you can scrape it away with your car keys without damage to the keys then something is wrong and I'm 
ed if I know what. It is cement and sand you're using?
Are you working off a set of drawings (without wishing to look like a poof)?
ed if I know what. It is cement and sand you're using? Are you working off a set of drawings (without wishing to look like a poof)?
Here's a little job ime doing at the moment,its restoring a football ground into a "Retro Football Ground",this end of the ground was all conifers,they were chopped down back in the summer and me and a couple of mates extended the brickwork which you can see with the different coloured bricks,ive since built the plywood screen structure and have been spending the last few months giving the Football ground a make over.
This photo was half way through the job,its all voluntary and a labour of love but its like trying to refloat a sinking battle ship and a huge challenge that ime relishing.
This photo was half way through the job,its all voluntary and a labour of love but its like trying to refloat a sinking battle ship and a huge challenge that ime relishing.
An extract from one of our company QA guides below, generally washing up liquid like a plasticser if added in too large quantities can act as a retarder which will slow the hyrdation of cement reacation down which as you have found will lead to your muck going off slowly. There a few things that probably do not cover your garage but then probably a few that do below.
Any Photos of the somme?
edit to say: Important that you use a gauge to ensure that your mixes are spot on.
Brickwork/Blockwork
• Ensure mortar mixes are suitable for brick/block and required durability. Mortar should generally be less than brick/block strength.
• BEWARE specifications which require maximum strengths for mortar. These cannot be complied with, especially using readymixed mortars.
• Check bricks and blocks are to specification including colour (blocks normally colour coded). Do not use dense blocks 140mm and above without adequate lifting arrangements (max 20kg).
• Has the work been detailed to “brick” size?
• Beware details of flashings in same joint as dpc. Extremely difficult to achieve correctly without damaging dpc. Seek advice or refer to BDA Manual “Achieving Successful Brickwork”.
• If mortar site mixed, sand and cement to be gauged (bucket/box).
• Take mortar cubes - special requirements for retarded mortars. If readymixed or silo, consider Bremor test as an early check. (Supply of Bremor equipment and reagents may be a problem).
• dpc/tray to be laid on full bed min 4mm, and MUST be visible.
• dpc/tray to be correctly fixed/jointed. Solvent adhesives best.
• Trays may need special cloaks around columns etc.
• Trays above window heads to turn up beyond window.
• Weep holes above trays at 900mm generally, horizontally.
• Ties to be embedded 50mm min and NOT slope inwards. Check order size.
• Ensure inner and outer skin gauge correctly, use gauge rods/datums.
• Ties at reveals/movement joint at 225mm c/c, vertically.
• Check tie centres required for insulation. READ THE PACKET.
• DO NOT shot fire into concrete. Plug and screw for any missing ties.
• DO NOT use full fill insulation in place of partial fill due to increased risk of the insulation sagging and bridging the cavity.
• Install insulation with top edge above lower leaf of masonry.
• ALL cavities and edge of insulation to be kept clean. Use battens or other system. It may be difficult, but is VERY important.
• Ensure perps are fully filled, and do NOT lay bricks with frogs down.
• Any masonry to be protected with RIW etc. must have joints flushed.
• Ensure type of tie is suitable for height of masonry.
• Ensure correct type of tie at movement joints.
• Do lintels need propping? Load from new masonry may overload. Check that lintels are installed correct way up (if applicable).
• Where possible always screw fix ties to steelwork, but shot firing may be acceptable - obtain “gun” supplier’s advice and carry out tests.
• Any brickwork on a support must not overhang by more than one third. • Beware concrete tolerances or out of line affecting support design.
• Avoid blockwork getting wet before or during construction. Increases risk of shrinkage cracking in finished work, and salt or lime deposits which are difficult to remove. • Protect new brickwork from rain to avoid lime staining.
• Ensure procedures for hot and cold weather working are detailed.
• Establish max height of lift in one day (normally 1.5m), but beware effects of wind on new work, and take precautions against collapse.
• Note: To help establish if dpcs are correctly located, assume internal face of external skin is always wet.
Any Photos of the somme?
edit to say: Important that you use a gauge to ensure that your mixes are spot on.
Brickwork/Blockwork
• Ensure mortar mixes are suitable for brick/block and required durability. Mortar should generally be less than brick/block strength.
• BEWARE specifications which require maximum strengths for mortar. These cannot be complied with, especially using readymixed mortars.
• Check bricks and blocks are to specification including colour (blocks normally colour coded). Do not use dense blocks 140mm and above without adequate lifting arrangements (max 20kg).
• Has the work been detailed to “brick” size?
• Beware details of flashings in same joint as dpc. Extremely difficult to achieve correctly without damaging dpc. Seek advice or refer to BDA Manual “Achieving Successful Brickwork”.
• If mortar site mixed, sand and cement to be gauged (bucket/box).
• Take mortar cubes - special requirements for retarded mortars. If readymixed or silo, consider Bremor test as an early check. (Supply of Bremor equipment and reagents may be a problem).
• dpc/tray to be laid on full bed min 4mm, and MUST be visible.
• dpc/tray to be correctly fixed/jointed. Solvent adhesives best.
• Trays may need special cloaks around columns etc.
• Trays above window heads to turn up beyond window.
• Weep holes above trays at 900mm generally, horizontally.
• Ties to be embedded 50mm min and NOT slope inwards. Check order size.
• Ensure inner and outer skin gauge correctly, use gauge rods/datums.
• Ties at reveals/movement joint at 225mm c/c, vertically.
• Check tie centres required for insulation. READ THE PACKET.
• DO NOT shot fire into concrete. Plug and screw for any missing ties.
• DO NOT use full fill insulation in place of partial fill due to increased risk of the insulation sagging and bridging the cavity.
• Install insulation with top edge above lower leaf of masonry.
• ALL cavities and edge of insulation to be kept clean. Use battens or other system. It may be difficult, but is VERY important.
• Ensure perps are fully filled, and do NOT lay bricks with frogs down.
• Any masonry to be protected with RIW etc. must have joints flushed.
• Ensure type of tie is suitable for height of masonry.
• Ensure correct type of tie at movement joints.
• Do lintels need propping? Load from new masonry may overload. Check that lintels are installed correct way up (if applicable).
• Where possible always screw fix ties to steelwork, but shot firing may be acceptable - obtain “gun” supplier’s advice and carry out tests.
• Any brickwork on a support must not overhang by more than one third. • Beware concrete tolerances or out of line affecting support design.
• Avoid blockwork getting wet before or during construction. Increases risk of shrinkage cracking in finished work, and salt or lime deposits which are difficult to remove. • Protect new brickwork from rain to avoid lime staining.
• Ensure procedures for hot and cold weather working are detailed.
• Establish max height of lift in one day (normally 1.5m), but beware effects of wind on new work, and take precautions against collapse.
• Note: To help establish if dpcs are correctly located, assume internal face of external skin is always wet.
Edited by ALawson on Wednesday 29th November 08:10
Edited by ALawson on Wednesday 29th November 08:14
ZR1cliff said:
Sounds good ,before you lay the damp proof membrane(DPM) down make sure to blind over with sand so any jagged edges of rubble dont punture the membrane.
Do you have any other frames in the structure if so try to have "head of frame" all on the same level/course if possible it gives a cleaner look.
Are you plastering/coating the garage or is it face block work.
Do you have any pics or plans to show on here.
Do you have any other frames in the structure if so try to have "head of frame" all on the same level/course if possible it gives a cleaner look.
Are you plastering/coating the garage or is it face block work.
Do you have any pics or plans to show on here.
I'll more than likely be rendering or pebble dashing the outside of it.
It is basically a 16 x 20 rectangle, not sure exactly what doors and windows will go it yet.
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