About the Barn
Where is the medieval monastic barn at Croxley Green?
see map

Croxley Great Barn is a hidden, almost forgotten, gem. It is situated just to the south of the London Underground Metropolitan line to Amersham close to its junction with the Watford branch, and in close proximity to Croxley Hall Wood where the original Croxley Manor* is believed to have been sited.

The barn is located on private land within playing fields belonging to St Joan of Arc School and access to view the barn must be sought from the school (telephone 01923 773881).

Indeed, it is now very difficult to get a clear sight of the barn due to relatively recent vegetation and hedge growth, the best point from which to view it in the splendour of its natural setting being the Ebury Way, the disused trackbed of the former LMS branch line from Watford to Rickmansworth. Here is a building with a long and significant history and of major architectural interest.

*Hertfordshire County Council Sites and Monuments Record No 828/874

A Tithe Barn?
Despite often being referred to as such, the barn is definitely NOT a tithe barn.

In medieval times tithe barns were used specifically to store the produce that was rendered to the parish priest in tithes [see below] by parishioners and were usually built near the parish church and/or the priest's house. The parish church of St Mary, Rickmansworth, served Croxley as well in those days. The barn is about 1000 metres Northeast of St Mary's, nowhere near the church, so even it’s physical location confirms that it was a monastic barn, not a tithe barn.

From the tenth century, tithes were a legal obligation. Tithes were one tenth of the produce of the parish which the priest served. They were payable each year. There were 2 main forms: great tithes - corn, lambs & fleeces (1/10 of all that was produced within the parish)
little tithes - apples, pears, flax, hemp, butter etc.

In towns (i.e. urban parishes) the little tithe could take the form of every tenth item produced, eg every tenth shoe from shoemaker, although this was usually commuted for cash. Tithes were NOT paid to monasteries or abbeys.

Heather Falvey

The Structure and Layout of the Barn

The barn, which is one of the largest of its type in Hertfordshire, measures 101ft by 40ft, consists of five weatherboarded bays and is aisled. The peghole tiled roof has half hipped gable ends and gablets. A contemporary timberframed gabled porch projects from the eastern side of the central bay. Two of the open trusses are of collar and tie beam type and those forming the central bay are of crownpost type. The crownposts are tall and square in sections, with single curved braces which spring from near the bottom of the post to the central purlin. The arcade posts are 13 inches square and the arch braces and passing braces are 6 inches and 42 inches thick respectively.

The aisles in the northern half of the barn are divided by sleeperbeams 9 ft 3 ins long by 13 ins wide resting on walls 4ft 10ins high, constructed of flint, Totternhoe clunch coping and in places brickwork. Because of the sloping ground the southern aisle partitions are higher and the southern external wall is 6ft 6ins high with remains of buttresses of flint faced in brickwork of a later date at the southwest corner. Midway between the principal wallposts are jowled wallposts, chamfered shores or secondary braces, 9 ins by 11 ins in section, and these are tenoned to the arcade plates. Tenoned to the shores and jointed to the wallplates are short squaresection ties. The right aisle tie and wallplate of the porch are one, and the supporting wallpost is not jowled.

The doors within the porch, which is in the centre of the eastern side of the barn, are large enough to admit a fully laden hay cart to pass over the flailing floor of 4 ins thick oak boards.

S Castle/L Leach

Schedule of Repairs and Costs (from Condition Survey)
Works anticipated within 0–5 years:
Replace west window and south door £2,500
Repair weatherboarding and decorate £10,000
Decorate gutters and downpipes £2,000
Minor pointing to plinths/removal of mortar from plinth cappings £1,000
Precautionary work to frame joints £1,000
Temporary supports to post bearings £1,000
Total £17,500

Works anticipated within 5–15 years:
Replacement of external cladding and studwork £40,000
Repairs to cill beam and post bearings £10,000
Repairs to plinth cappings £15,000
Overhauling roof covering £1,000
Reduce ground level to north wall and install surface water drainage £5,000
Total £71,000

Costs are for budget purposes only at 2005 base date. All works recommended are subject to consultation and agreement of Local Authority and English Heritage.

Dating the Barn

A grade II* listed building, Croxley Great Barn is a timberframed aisled barn with a crownpost roof. It is one of a group of stylistically similar barns in the vicinity of St Albans.

Although the barn underwent restoration in 1972/75, it remains remarkably complete. It is of particular interest in that it has a number of crucklike intermediate arcade shores set at half bay intervals which look a little like basecrucks. They are braced back to the aisle wall posts by `stubties' that appear original, but at their tops they only cradle the arcade plates. There remains some doubt about whether or not these features are original. The passingbraces rise to stop at tie beam level. The crownpost/purlin support was apparently only set over the midstrey bay. All the tie beams are slightly cambered, though the collars are not.

Dating was therefore commissioned by English Heritage in order to try and establish the date for this barn, thus effectively dating the other similar barns in the vicinity, and to see if dendrochronology would be able to settle the discussion about whether or not the intermediate arcade shores were original.

Despite the use of relatively fastgrown young oak trees to provide the large timbers in this barn, dendrochronological dating was possible. Some timbers exhibited unusual growth patterns and these could not be dated. This implies that some of the timbers may have been managed, suffered disease, or insect defoliation, during their lifetime.

Only one sample retained complete sapwood, giving a felling date of the winter AD 1397/8. Three of the other timbers which dated crossmatched well with each other and appeared to have come from a single group of timbers, perhaps representing a single woodland source. The other dated timbers exhibited likely felling dates which incorporated winter AD 1397/8, and it seems likely that they were all felled at the same time.

This date agrees well with the historical records suggesting that the barn was most likely to have been constructed during John Moote's abbacy. One intermediate arcade shore was dated, this being one of the four timbers in the site chronology. This shows that these unusual features were indeed part of the original build of the barn.

Dr M Bridge

Further Research: The Archaeology

Perhaps the first question that presents itself is whether the existing floor level is now well above the original 14c floor and how the original threshing floor has fared. A geophysics record of the floor area might also provide evidence of any previous structure within the present walls whilst some environmental sampling at the original floor base could be very informative.

The structural timbers were usually ‘marked’ prior to and for assembly and identified again when a sequence of erection of the sections was determined: It may be that such ‘signatures’, given the specialist skills of the carpenters are identical to those on the timbers of other barns built about the same time (e.g. Harpendenbury).

Some of the roof tiles (approx 15,000) will surely be original handmade 14c: archaeo-magnetic dating and /or thermo-luminescent analysis should be instructive. It must also be questioned as archaeologist Dr Jonathan Hunn has speculated- was the very high rake of the roof evidence that it was originally thatched? Close examination of original roof timbers may offer support for this possibility.

Externally it should be remembered that ‘100 marks were allocated for a Barn and associated buildings’ Geophysics of the surrounding land may yet yield evidence of the footprint of those buildings (possibly timber structures) as also of Tile Kilns if the massive quantities of roof tiles needed, were produced in-situ.

Two further associated matters worthy of exploration arise: was All Saints Lane (through Croxley Hall Wood) perhaps an ancient highway to the Manor of Croxley thence to the (later) adjacent Barn- mediaeval/anglo-saxon or even Iron age? Some test trenches could provide evidence. In the 60’s according to Herts S&M Record no 874 ’a large quantity of mediaeval pottery dating to 15c’ was discovered in the wood. The claim then: that it must be associated with the original Manor within what is now woodland but totally obliterated (robbed out for local building materials?) as John Caius who purchased the Manor in 1557 had no use for it. In 1327 in monastic times, newly appointed Abbot Richard of Wallingford is recorded as returning from his confirmation as Abbot by the Pope at Avignon via ‘his Manor of Crokesly for rest and repose’ before proceeding to St Albans. (The present whereabouts and circumstances of the pottery finds, who authenticated them etc, is unfortunately not now known.)

Two further isolated finds may add to the significance of the wood: a lead seal (bulla) of Pope Alexander III (1159-1181) was found in rubble taken from a demolished property close to the present wood (The Rickmansworth Historian No14, 1967)

Part of a dagger or sword scabbard- the metal tip (or chape) was also found in the wood in 1980- dated by the BM between 1360-1450 and is now on display in the Three Rivers Museum.